Hydrogen peroxide and peracetic acid indicators and methods

ABSTRACT

The present invention provides a hydrogen peroxide indicator and a peracetic acid indicator that include a substrate on which is disposed an indicator composition that includes at least one of a select group of colorants and a transition metal salt. As a result of exposure to hydrogen peroxide and/or peracetic acid, the colorants change color, and even become colorless, thereby providing an indication of the presence of hydrogen peroxide and/or peracetic acid.

BACKGROUND OF THE INVENTION

[0001] Medical instruments, particularly surgical instruments, aretypically sterilized prior to use using steam or othersterilizing/disinfecting gases or liquids. A traditional sterilizationprocess uses steam under pressure. Alternative sterilization processesuse ethylene oxide or hydrogen peroxide in vapor form as the sterilant.

[0002] The use of hydrogen peroxide and other chemical vapor phasesterilization techniques typically involve operating temperatures wellbelow those associated with steam sterilization. These “low temperature”technologies generally operate at temperatures below about 80° C., andoften below about 65° C. For hydrogen peroxide sterilization, thesterilized goods are typically available for use shortly after thecompletion of the sterilization cycle. This is because the decompositionproducts (e.g., water and oxygen) are nontoxic. The potency of thehydrogen peroxide may be augmented by the presence of electrical energyin the form of an ionizing plasma field.

[0003] An alternative sterilization process uses a liquid phaseperacetic acid solution. Such sterilization processes may be performedin a sterilization chamber. During a typical sterilization cycle, anarticle to be sterilized is exposed to a sterilization solutioncontaining, for example, about 2000 parts per million (ppm) to 2500 ppmof peracetic acid. The article is exposed to the solution for asufficient time at a sufficiently high temperature, e.g., 50° C.-60° C.,for the sterilization to be effective.

[0004] Sterilization indicators are used to monitor whether asterilization process has been performed. Sterilization indicatorstypically include an indicator composition, carried on a substrate, thatchanges color during the sterilization process. Conventional indicatorsfor hydrogen peroxide, however, often fade upon exposure to light. Thus,there is still a need for suitable indicators that include color changecompositions for indicating the sterilization of articles using hydrogenperoxide or peracetic acid.

SUMMARY OF THE INVENTION

[0005] The present invention is directed to indicators and methods fordetecting the presence of, and for monitoring sterilization processesutilizing, a sterilant, including a hydrogen peroxide and/or a peraceticacid sterilant. The indicators and methods include an indicatorincluding a substrate and an indicator composition disposed thereon,wherein the indicator composition includes at least one colorant thatchanges color when exposed to a sterilant, at least one binder resin,and at least one salt of a transition metal.

[0006] In a preferred embodiment of the invention, the transition metalis selected from the group consisting of Group VB, Group VII, and GroupIB transition metals, and combinations thereof. The sterilizationindicators of the present invention preferably include colorants thatchange color when exposed to hydrogen peroxide and/or peracetic acid.The sterilization indicators of the present invention preferably includea colorant selected from the group of classes of colorants consisting ofMethane, Monoazo, Diazo, Triazo, Diazine, Thiazine, Xanthene, Oxazine,Cyanine, Anthraquinone, Benzodifuranone, Styryl, Phthalocyanine,Quinophthalone, Nitro, and Nitroso colorants, and combinations thereof,and/or a colorant selected from the group consisting of Victoria green Sextra, Basic blue 41, Basic red 15, Acid green AX986, Keystone soapfluoro green, and Basic red 14 colorants, and combinations thereof.Therefore, a sterilization indicator of the present invention mayinclude a colorant that includes, for instance, a combination of aMethane and a Diazo colorant, a combination of Basic blue 41 and Basicred 15, or a combination of a Methane colorant and Basic blue 41. Aneven more preferred sterilization indicator includes an indicatorcomposition further including at least one colorant that does not changecolor when exposed to a sterilant, preferably hydrogen peroxide.

[0007] In one embodiment, the present invention is directed to methodsand indicators for detecting the presence of hydrogen peroxide,preferably hydrogen peroxide in the vapor phase. The methods andindicators are particularly well suited for monitoring whether ahydrogen peroxide sterilization process has been performed.

[0008] In another embodiment, the present invention is directed tomethods and indicators for detecting the presence of peracetic acid. Theperacetic acid can be in the liquid phase or in the vapor phase.Preferably, the peracetic acid is in the liquid phase. The methods andindicators are well suited for monitoring whether a peracetic acidsterilization process has been performed.

[0009] The present invention provides a hydrogen peroxide indicator anda peracetic acid indicator that include a substrate and an indicatorcomposition disposed thereon, wherein the indicator composition includesat least one colorant, at least one metal salt, and at least one binderresin. Preferably, the metal salt is a transition metal salt. Morepreferably, the transition metal salt includes one or more metals fromGroups VIB, VIII, and IB of the Periodic Chart, including iron, copper,cobalt, and chromium. Even more preferably, the transition metal saltincludes metals from Groups VIII and IB of the Periodic Chart, includingiron, copper, and cobalt, and combinations thereof. Most preferably, thetransition metal salt includes iron and/or copper. The salts can includeinorganic or organic anions. Examples include chloride, acetate,sulfate, chromate, iodate, molybdate, nitrate, oxalate, citrate,propionate, lactate, malate, tartrate, and benzoate. Preferred anionsinclude chloride, acetate, and sulfate.

[0010] In a preferred embodiment, the hydrogen peroxide indicatorincludes: at least one salt of a transition metal; at least one colorantselected from the group of classes of colorants consisting of Methane,Monoazo, Diazo, Triazo, Diazine, Thiazine, Xanthene, Oxazine, andAnthraquinone colorants, and combinations thereof, and/or at least onecolorant selected from the group consisting of Victoria green S extra,Basic blue 41, Basic red 15, Acid green AX986, Keystone soap fluorogreen, Basic red 14, and combinations thereof; and at least one binderresin. In a more preferred embodiment, the transition metal salt isselected from the group consisting of a copper salt, a cobalt salt, aniron salt, a chromium salt, and combinations thereof. In an even morepreferred embodiment, the transition metal salt is at least one ironsalt. In a still more preferred embodiment, the colorant is selectedfrom the group consisting of Patent blue violet, Alkali blue 4B,Victoria pure blue BO, Acid fuchsin sodium salt, Alphazurine A, Methylviolet 2B, Ethyl violet, FD/C blue 1, Brilliant blue R, Lissamine greenB, Erioglaucine, Eriochrome black T, Eriochrome blue black B, Cibacronbrilliant red 3B, Chromotrope 2B, Amaranth, D&C red No. 33, Bordeaux R,Acid violet 7, Acid violet 5, Plasmocorinth B, Acid Blue 113, Acid red151, Acid black 24, Acid red 97, Direct red 75, Brilliant crocein MOO,Ponceau SS, Reactive black 5, Arsenazo 111, Direct blue 71, AzocarmineG, Methylene violet 3RAX, Toluidine blue O, Methylene green,Sulforhodamine B, Rhodanine 6G, Violamine R, Nile blue A, Basic blue 3,Brilliant cresyl blue BB, Basic red 15, Alizarin violet 3R, Victoriagreen S extra, Basic blue 41, Acid green AX986, Keystone soap fluorogreen, Basic red 14, D&C green No. 5, and combinations thereof. In aneven more preferred embodiment, the colorant is selected from the groupconsisting of Victoria pure blue BO, Acid fuchsin sodium salt,Alphazurine A, Methyl violet 2B, Ethyl violet, FD/C blue 1, Brilliantblue R, Lissamine green B, Erioglaucine, Eriochrome black T, Eriochromeblue black B, Cibacron brilliant red 3B, Chromotrope 2B, D&C red No. 33,Acid violet 7, Acid violet 5, Plasmocorinth B, Acid blue 113, Acid red151, Acid black 24, Acid red 97, Direct red 75, Brilliant crocein MOO,Ponceau SS, Reactive black 5, Arsenazo 111, Azocarmine G, Methyleneviolet 3RAX, Toluidine blue O, Methylene green, Sulforhodamine B,Rhodanine 6G, Violamine R, Nile blue A, Basic blue 3, Brilliant cresylblue BB, Basic red 15, Alizarin violet 3R, Victoria green S extra, Basicblue 41, Acid green AX986, Keystone soap fluoro green, Basic red 14, D&Cgreen No. 5, and combinations thereof. In a still more preferredembodiment, the hydrogen peroxide indicator includes an indicatorcomposition that further includes at least one colorant that does notchange color when exposed to hydrogen peroxide vapor.

[0011] In another preferred embodiment, the hydrogen peroxide indicatorincludes a substrate and an indicator composition disposed thereon,wherein the indicator composition includes: at least one salt of cobalt,copper, chromium, and combinations thereof; at least one colorant thatchanges color when exposed to hydrogen peroxide vapor; and at least onebinder resin. In a preferred embodiment, the salt is selected from thegroup consisting of cobalt chloride, cobalt acetate, cupric chloride,cupric sulfate, cupric acetate, chromium potassium sulfate, andcombinations thereof. In another preferred embodiment, the colorant isselected from the group of classes of colorants consisting of Methane,Monoazo, Diazo, Triazo, Diazine, Thiazine, Cyanine, Xanthene, Oxazine,and Anthraquinone colorants, and combinations thereof, and/or thecolorant is selected from the group consisting of Victoria green Sextra, Basic blue 41, Basic red 15, Acid green AX986, Keystone soapfluoro green, Basic red 14, and combinations thereof. In a furtherpreferred embodiment, the indicator composition additionally includes atleast one colorant that does not change color when exposed to hydrogenperoxide.

[0012] In another preferred embodiment, the hydrogen peroxide indicatorincludes a substrate and an indicator composition disposed thereon,wherein the indicator composition includes at least one cobalt salt, atleast one colorant that changes color when exposed to hydrogen peroxidevapor, and at least one binder resin. In a more preferred embodiment,the colorant is selected from the group of classes of colorantsconsisting of Methane, Monoazo, Diazo, Oxazine, and Anthraquinonecolorants, and combinations thereof. In an even more preferredembodiment, the colorant is selected from the group consisting of Patentblue violet, Aniline blue, Erioglaucine, Arsenazo 1, Acid blue 92,Eriochrome blue black B, Congo red, Acid blue 29, Nile blue A, Reactiveblue 2, Basic red 15, D&C green No. 5, and combinations thereof.

[0013] In another preferred embodiment, the hydrogen peroxide indicatorincludes a substrate and an indicator composition disposed thereon,wherein the indicator composition includes at least one copper salt, atleast one colorant that changes color when exposed to hydrogen peroxidevapor, and at least one binder resin. In a more preferred embodiment,the colorant is selected from the group of classes of colorantsconsisting of Methane, Monoazo, Diazo, Triazo, Diazine, Thiazine,Xanthene, Oxazine, Cyanine, and Anthraquinone colorants, andcombinations thereof, and/or the colorant is selected from the groupconsisting of Victoria green S extra, Basic blue 41, Basic red 15, Acidgreen AX986, Keystone soap fluoro green, Basic red 14, and combinationsthereof. In an even more preferred embodiment, the colorant is selectedfrom the group consisting of Alphazurine A, Methyl violet 2B, Ethylviolet, FD/C blue 1, Brilliant blue R, Lissamine green B, Erioglaucine,Victoria pure blue BO, Acid fuchsin sodium salt, Patent blue violet,Guinea green B, Coomassie violet R 150, Mordant brown 48, Chromotrope2B, D&C red No. 33, Bordeaux R, Acid violet 7, Acid violet 5,Plasmocorinth, Acid red 151, Acid blue 29, Acid black 24, Acid red 97,Direct red 75, Brilliant crocein MOO, Ponceau SS, Reactive black 5,Arsenazo 111, Direct blue 71, Azocarmine G, Methylene violet 3RAX,Toluidine blue O, Azure B, Methylene green, Sulforhodamine B, Rhodanine6G, Violamine R, Nile blue A, Basic blue 3, Brilliant cresyl blue BB,Quinaldine red, Basic red 15, Alizarin violet 3R, Reactive blue 2,Victoria green S extra, Basic blue 41, Acid green AX986, Keystone soapfluoro green, Basic red 14, D&C green No. 5, Fast green FCF, andcombinations thereof. In a still more preferred embodiment, the colorantis selected from the group of classes of colorants consisting ofMethane, Monoazo, Diazo, Diazine, Thiazine, Xanthene, Oxazine, andCyanine colorants, and combinations thereof, and/or the colorant isselected from the group consisting of Victoria green S extra, Basic blue41, Basic red 15, Acid green AX986, Keystone soap fluoro green, Basicred 14, and combinations thereof. In a most preferred embodiment, thecolorant is selected from the group consisting of Alphazurine A, Methylviolet 2B, Ethyl violet, FD/C blue 1, Brilliant blue R, Lissamine greenB, Erioglaucine, Victoria pure blue BO, Acid fuchsin sodium salt,Coomassie violet R 150, Mordant brown 48, Acid violet 5, Plasmocorinth,Acid red 151, Acid blue 29, Acid black 24, Acid red 97, Direct red 75,Arsenazo 111, Azocarmine G, Methylene violet 3RAX, Toluidine blue O,Methylene green, Rhodanine 6G, Basic blue 3, Brilliant cresyl blue BB,Quinaldine red, Basic red 15, Reactive blue 2, Victoria green S extra,Basic blue 41, Keystone soap fluoro green, Basic red 14, D&C green No.5, and combinations thereof.

[0014] In another preferred embodiment, the hydrogen peroxide indicatorincludes a substrate and an indicator composition disposed thereon,wherein the indicator composition includes at least one chromium salt,at least one colorant that changes color when exposed to hydrogenperoxide vapor, and at least one binder resin. In a more preferredembodiment, the colorant is selected from the group of classes ofcolorants consisting of Methane, Monoazo, Diazo, and Cyanine colorants,and combinations thereof. In an even more preferred embodiment, thecolorant is selected from the group consisting of Ethyl violet,Eriochrome black T, Eriochrome blue black B, Congo red, Acid blue 113,Quinaldine red, and combinations thereof. In a still more preferredembodiment, the colorant is selected from the group consisting of Ethylviolet, Eriochrome black T, Eriochrome blue black B, Acid blue 113,Quinaldine red, and combinations thereof.

[0015] In another embodiment, the present invention provides a peraceticacid indicator that includes a substrate and an indicator compositiondisposed thereon, wherein the indicator composition includes: at leastone transition metal salt; at least one colorant selected from the groupof classes of colorants consisting of Monoazo and Diazo colorants, andcombinations thereof, and/or at least one colorant selected from thegroup consisting of Victoria green S extra, Basic blue 41, Basic red 15,Acid green AX986, Keystone soap fluoro green, Basic red 14, andcombinations thereof; and at least one binder resin. In a preferredembodiment the indicator composition further includes at least onecolorant that does not change color when exposed to peracetic acid.

[0016] In a preferred embodiment, the peracetic acid indicator includesa substrate and an indicator composition disposed thereon, wherein theindicator composition includes: at least one salt of copper, cobalt, andcombinations thereof; at least one colorant that changes color whenexposed to peracetic acid, preferably liquid peracetic acid; and atleast one binder resin. In a more preferred embodiment, the indicatorcomposition further includes at least one colorant that does not changecolor when exposed to peracetic acid.

[0017] In another preferred embodiment, the peracetic acid indicatorincludes a substrate and an indicator composition disposed thereon,wherein the indicator composition includes at least one copper salt, atleast one colorant that changes color when exposed to peracetic acid,preferably liquid peracetic acid, and at least one binder resin. In amore preferred embodiment, the colorant is selected from the group ofclasses of colorants consisting of Monoazo and Diazo colorants, andcombinations thereof, and/or the colorant is selected from the groupconsisting of Victoria green S extra, Basic blue 41, Basic red 15, Acidgreen AX986, Keystone soap fluoro green, Basic red 14, and combinationsthereof. In an even more preferred embodiment, the colorant is selectedfrom the group consisting of Acid violet 7, Evans blue, Naphthol blueblack, Reactive black 5, Brilliant black BN, Azocarmine B, andcombinations thereof.

[0018] In another preferred embodiment, the peracetic acid indicatorincludes a substrate and an indicator composition disposed thereon,wherein the indicator composition includes at least one cobalt salt, atleast one colorant that changes color when exposed to peracetic acid,preferably liquid peracetic acid, and at least one binder resin. In amore preferred embodiment, the colorant is selected from the group ofclasses of colorants consisting of Monoazo and Diazo colorants, andcombinations thereof. In an even more preferred embodiment, the colorantis selected from the group consisting of Cibacron brilliant red 3B,Evans blue, Reactive black 5, Brilliant black BN, and combinationsthereof.

[0019] The invention also provides methods of monitoring a sterilizationprocess, including a hydrogen peroxide sterilization process and aperacetic acid sterilization process. These methods include: providingan indicator including an indicator composition including at least onesalt of a transition metal, at least one colorant that changes colorwhen exposed to a sterilant, and at least one binder resin; providing anarticle to be sterilized; and exposing the article to be sterilized andthe indicator to a sterilant. The sterilant preferably includes hydrogenperoxide, preferably hydrogen peroxide vapor and/or peracetic acid,preferably liquid peracetic acid.

[0020] A method of monitoring a hydrogen peroxide sterilization processof the present invention includes: providing a hydrogen peroxideindicator including a substrate and an indicator composition disposedthereon that includes at least one salt of a transition metal, at leastone colorant selected from the group of classes of colorants consistingof Methane, Monoazo, Diazo, Triazo, Diazine Thiazine, Cyanine, Xanthene,Oxazine, Anthraquinone, Benzodifuranone, Styryl, Phthalocyanine,Quinophthalone, Nitro, and Nitroso colorants, and combinations thereof,and/or at least one colorant selected from the group consisting ofVictoria green S extra, Basic blue 41, Basic red 15, Acid green AX986,Keystone soap fluoro green, Basic red 14, and combinations thereof, andat least one binder resin; providing an article to be sterilized; andexposing the hydrogen peroxide indicator and the article to besterilized to hydrogen peroxide vapor. In a more preferred method, thesalt of a transition metal is selected from the group consisting ofcupric chloride, ferrous chloride, cobalt chloride, cobalt acetate,cupric sulfate, ferrous sulfate, chromium potassium sulfate, cupricacetate, and combinations thereof. In an even more preferred method, theindicator composition further includes a colorant that does not changecolor when exposed to hydrogen peroxide vapor.

[0021] In a preferred method of the present invention, the methodincludes: providing a hydrogen peroxide indicator including a substrateand an indicator composition disposed thereon that includes at least onesalt of copper, chromium, iron, cobalt, and combinations thereof, atleast one colorant that changes color when exposed to hydrogen peroxidevapor, and at least one binder resin; providing an article to besterilized; and exposing the hydrogen peroxide indicator and the articleto be sterilized to hydrogen peroxide vapor. In a more preferred method,the colorant is selected from the group of classes of colorantsconsisting of Methane, Monoazo, Diazo, Triazo, Diazine, ThiazineCyanine, Xanthene, Oxazine, and Anthraquinone colorants, andcombinations thereof, and/or the colorant is selected from the groupconsisting of Victoria green S extra, Basic blue 41, Basic red 15, Acidgreen AX986, Keystone soap fluoro green, Basic red 14, and combinationsthereof.

[0022] Another preferred method includes providing a hydrogen peroxideindicator including a substrate and an indicator composition disposedthereon that includes at least one cobalt salt, at least one colorantthat changes color when exposed to hydrogen peroxide vapor, and at leastone binder resin, providing an article to be sterilized, and exposingthe hydrogen peroxide indicator and the article to be sterilized tohydrogen peroxide vapor. In a more preferred method, the colorant isselected from the group of classes of colorants consisting of Methane,Monoazo, Diazo, Oxazine, and Anthraquinone colorants, and combinationsthereof. In an even more preferred method, the colorant is selected fromthe group consisting of Patent blue violet, Aniline blue, Erioglaucine,Arsenazo 1, Acid blue 92, Eriochrome blue black B, Congo red, Acid blue29, Nile blue A, Reactive blue 2, Basic red 15, D&C green No. 5, andcombinations thereof.

[0023] Another preferred method includes providing a hydrogen peroxideindicator including a substrate and an indicator composition disposedthereon that includes at least one copper salt, at least one colorantthat changes color when exposed to hydrogen peroxide vapor, and at leastone binder resin, providing an article to be sterilized, and exposingthe hydrogen peroxide indicator and the article to be sterilized tohydrogen peroxide vapor. In a more preferred method, the colorant isselected from the group of classes of colorants consisting of Methane,Monoazo, Diazo, Triazo, Diazine, Thiazine, Xanthene, Oxazine, Cyanine,and Anthraquinone colorants, and combinations thereof, and/or thecolorant is selected from the group consisting of Victoria green Sextra, Basic blue 41, Basic red 15, Acid green AX986, Keystone soapfluoro green, Basic red 14, and combinations thereof. In an even morepreferred method, the colorant is selected from the group consisting ofAlphazurine A, Methyl violet 2B, Ethyl violet, FD/C blue 1, Brilliantblue R, Lissamine green B, Erioglaucine, Victoria pure blue BO, Acidfuchsin sodium salt, Patent blue violet, Guinea green B, Coomassieviolet R 150, Mordant brown 48 Chromotrope 2B, D&C red No. 33, BordeauxR, Acid violet 7, Acid violet 5, Plasmocorinth, Acid red 151, Acid blue29, Acid black 24, Acid red 97, Direct red 75, Brilliant crocein MOO,Ponceau SS, Reactive black 5, Arsenazo 111, Direct blue 71, AzocarmineG, Methylene violet 3RAX, Toluidine blue O, Azure B, Methylene green,Sulforhodamine B, Rhodanine 6G, Violamine R, Nile blue A, Basic blue 3,Brilliant cresyl blue BB, Quinaldine red, Basic red 15, Alizarin violet3R, Reactive blue 2, Victoria green S extra, Basic blue 41, Acid greenAX986, Keystone soap fluoro green, Basic red 14, D&C green No. 5, Fastgreen FCF, and combinations thereof. In a still more preferred method,the colorant is selected from the group consisting of Alphazurine A,Methyl violet 2B, Ethyl violet, FD/C blue 1, Brilliant blue R, Lissaminegreen B, Erioglaucine, Victoria pure blue BO, Acid fuchsin sodium salt,Coomassie violet R 150, Mordant brown 48, Acid violet 5, Plasmocorinth,Acid red 151, Acid blue 29, Acid black 24, Acid red 97, Direct red 75,Arsenazo 111, Azocarmine G, Methylene violet 3RAX, Toluidine blue O,Methylene green, Rhodanine 6G, Basic blue 3, Brilliant cresyl blue BB,Quinaldine red, Basic red 15, Reactive blue 2, Victoria green S extra,Basic blue 41, Keystone soap fluoro green, Basic red 14, D&C green No.5, and combinations thereof.

[0024] Another preferred method includes providing a hydrogen peroxideindicator including a substrate and an indicator composition disposedthereon that includes at least one iron salt, at least one colorant thatchanges color when exposed to hydrogen peroxide vapor, and at least onebinder resin, providing an article to be sterilized, and exposing thehydrogen peroxide indicator and the article to be sterilized to hydrogenperoxide vapor. In a more preferred method, the colorant is selectedfrom the group of classes of colorants consisting of Methane, Monoazo,Diazo, Triazo, Diazine, Thiazine, Cyanine, Xanthene, Oxazine, andAnthraquinone colorants, and combinations thereof, and/or the colorantis selected from the group consisting of Victoria green S extra, Basicblue 41, Basic red 15, Acid green AX986, Keystone soap fluoro green,Basic red 14, and combinations thereof. In an even more preferredmethod, the colorant is selected from the group consisting of Patentblue violet, Alkali blue 4B, Victoria pure blue BO, Acid fuchsin sodiumsalt, Alphazurine A, Methyl violet 2B, Ethyl violet, FD/C blue 1,Brilliant blue R, Lissamine green B, Erioglaucine, Eriochrome black T,Eriochrome blue black B, Cibacron brilliant red 3B, Chromotrope 2B,Amaranth, D&C red No. 33, Bordeaux R, Acid violet 7, Acid violet 5,Plasmocorinth B, Acid blue 113, Acid red 151, Acid black 24, Acid red97, Direct red 75, Brilliant crocein MOO, Ponceau SS, Reactive black 5,Arsenazo 111, Direct blue 71, Azocarmine G, Methylene violet 3RAX,Toluidine blue O, Methylene green, Sulforhodamine B, Rhodanine 6G,Violamine R, Nile blue A, Basic blue 3, Brilliant cresyl blue BB,Quinaldine red, Basic red 15, Alizarin violet 3R, Victoria green Sextra, Basic blue 41, Acid <green AX986, Keystone soap fluoro green,Basic red 14, D&C green No. 5, and combinations thereof. In a still morepreferred method, the colorant is selected from the group consisting ofVictoria pure blue BO, Acid fuchsin sodium salt, Alphazurine A, Methylviolet 2B, Ethyl violet, FD/C blue 1, Brilliant blue R, Lissamine greenB, Erioglaucine, Eriochrome black T, Eriochrome blue black B, Cibacronbrilliant red 3B, Chromotrope 2B, D&C red No. 33, Acid violet 7, Acidviolet 5, Plasmocorinth B, Acid blue 113, Acid red 151, Acid black 24,Acid red 97, Direct red 75, Brilliant crocein MOO, Ponceau SS, Reactiveblack 5, Arsenazo 111, Azocarmine G, Methylene violet 3RAX, Toluidineblue O, Methylene green, Sulforhodamine B, Rhodanine 6G, Violamine R,Nile blue A, Basic blue 3, Brilliant cresyl blue BB, Basic red 15,Alizarin violet 3R, Victoria green S extra, Basic blue 41, Acid greenAX986, Keystone soap fluoro green, Basic red 14, D&C green No. 5, andcombinations thereof.

[0025] Another preferred method includes providing a hydrogen peroxideindicator including a substrate and an indicator composition disposedthereon that includes at least one chromium salt, at least one colorantthat changes color when exposed to hydrogen peroxide vapor, and at leastone binder resin, providing an article to be sterilized, and exposingthe hydrogen peroxide indicator and the article to be sterilized tohydrogen peroxide vapor. In a more preferred method, the colorant isselected from the group of classes of colorants consisting of Methane,Monoazo, Diazo, and Cyanine colorants, and combinations thereof. In aneven more preferred method, the colorant is selected from the groupconsisting of Ethyl violet, Eriochrome black T, Eriochrome blue black B,Congo red, Acid blue 113, Quinaldine red, and combinations thereof. In astill more preferred method, the colorant is selected from the groupconsisting of Ethyl violet, Eriochrome black T, Eriochrome blue black B,Acid blue 113, Quinaldine red, and combinations thereof.

[0026] A preferred method of monitoring a sterilization process of thepresent invention includes: providing a peracetic acid indicatorincluding a substrate and an indicator composition disposed thereon thatincludes at least one salt of a transition metal, at least one colorantselected from the group of classes of colorants consisting of Monoazo,Diazo, Benzodifuranone, Styryl, Phthalocyanine, Quinophthalone, Nitro,and Nitroso colorants, and combinations thereof, and/or at least onecolorant selected from the group consisting of Victoria green S extra,Basic blue 41, Basic red 15, Acid green AX986, Keystone soap fluorogreen, Basic red 14, and combinations thereof, and at least one binderresin; providing an article to be sterilized; and exposing the peraceticacid indicator and the article to be sterilized to peracetic acid,preferably liquid peracetic acid. In a more preferred method, the saltof a transition metal is selected from the group consisting of cupricacetate, cobalt acetate, cupric sulfate, and combinations thereof.

[0027] In a preferred method of the present invention, the methodincludes: providing a peracetic acid indicator including a substrate andan indicator composition disposed thereon that includes at least onesalt of copper, cobalt, and combinations thereof, at least one colorantthat changes color when exposed to peracetic acid, and at least onebinder resin; providing an article to be sterilized; and exposing theperacetic acid indicator and the article to be sterilized to peraceticacid, preferably liquid peracetic acid. In a more preferred method, thecolorant is selected from the group of classes of colorants consistingof Monoazo and Diazo colorants, and combinations thereof, and/or thecolorant is selected from the group consisting of Victoria green Sextra, Basic blue 41, Basic red 15, Acid green AX986, Keystone soapfluoro green, Basic red 14, and combinations thereof.

[0028] In a preferred method of the present invention, the methodincludes: providing a peracetic acid indicator including a substrate andan indicator composition disposed thereon that includes at least onecopper salt, at least one colorant that changes color when exposed toperacetic acid, and at least one binder resin; providing an article tobe sterilized; and exposing the peracetic acid indicator and the articleto be sterilized to peracetic acid, preferably liquid peracetic acid. Ina more preferred method, the colorant is selected from the group ofclasses of colorants consisting of Monoazo and Diazo colorants, andcombinations thereof, and/or the colorant is selected from the groupconsisting of Victoria green S extra, Basic blue 41, Basic red 15, Acidgreen AX986, Keystone soap fluoro green, Basic red 14, and combinationsthereof. In a still more preferred method, the colorant is selected fromthe group consisting of Acid violet 7, Evans blue, Naphthol blue black,Reactive black 5, Brilliant black BN, Azocarmine B, and combinationsthereof.

[0029] In another preferred method of the present invention, the methodincludes: providing a peracetic acid indicator including a substrate andan indicator composition disposed thereon that includes at least onecobalt salt, at least one colorant that changes color when exposed toperacetic acid, and at least one binder resin; providing an article tobe sterilized; and exposing the peracetic acid indicator and the articleto be sterilized to peracetic acid preferably liquid peracetic acid. Ina more preferred method, the colorant is selected from the groupconsisting of Monoazo and Diazo colorants and combinations thereof. In astill more preferred method, the colorant is selected from the groupconsisting of Cibacron brilliant red 3B, Evans blue, Reactive black 5,Brilliant black BN, and combinations thereof.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS

[0030] In one embodiment, the present invention provides a sterilantindicator that includes a substrate on which is disposed an indicatorcomposition that includes at least one metal salt, preferably atransition metal salt, at least one of a select group of colorants, andat least one binder resin. Preferably, the sterilant is hydrogenperoxide and/or peracetic acid. As a result of exposure to a sterilant,the colorants change color, and even become colorless, thereby providingan indication of the presence of the sterilant and a method formonitoring a sterilization process.

[0031] One embodiment of the invention provides a hydrogen peroxideindicator that includes a substrate on which is disposed an indicatorcomposition that includes at least one transition metal salt and atleast one of a select group of colorants that changes color when exposedto hydrogen peroxide, and at least one binder resin. As a result ofexposure to hydrogen peroxide, the colorants change color, and evenbecome colorless, providing an indication of hydrogen peroxide presence.

[0032] In another embodiment, the present invention provides a peraceticacid indicator that includes a substrate on which is disposed anindicator composition that includes at least one metal salt, preferablya transition metal salt, at least one of a select group of colorantsthat changes color when exposed to peracetic acid, and at least onebinder resin. As a result of exposure to peracetic acid, the colorantschange color, thereby providing an indication of the presence ofperacetic acid.

[0033] In particular, the present invention is directed to a system forindicating exposure to a hydrogen peroxide vapor sterilization processor a peracetic acid sterilization process, which may use either liquidperacetic acid or peracetic acid vapor. In one embodiment, the indicatorcomposition includes at least one component that is transformed(typically, chemically transformed) when exposed to hydrogen peroxidevapor such that the color of the composition changes. In anotherembodiment, the indicator composition includes at least one componentthat is transformed (typically, chemically transformed) when exposed toliquid peracetic acid and/or peracetic acid vapor, preferably liquidperacetic acid, such that the color of the composition changes. Thecompositions may include one or more components that change color whenexposed to hydrogen peroxide and/or peracetic acid, as well as othercomponents that do not change color when exposed to hydrogen peroxideand/or peracetic acid. The composition preferably includes a polymericbinder resin to aid in applying the composition to a suitable substrate.

[0034] Indicators of the present invention are very useful to show whenan article has been exposed to hydrogen peroxide and/or peracetic acid.Significantly, indicators of the present invention offer one a simple,yet effective means for indicating when a particular article has beensubjected to sterilization using hydrogen peroxide vapor and/or liquidperacetic acid or peracetic acid vapor.

[0035] Preferably, the hydrogen peroxide indicator compositions of thepresent invention undergo a color change when exposed to an atmosphereabove an aqueous solution containing 30 weight percent (wt-%) hydrogenperoxide at 50° C. within a period of at least about one hour and/or acolor change when exposed to an atmosphere containing about 6milligrams/liter (mg/l) to about 7 mg/l hydrogen peroxide (in an emptychamber, i.e., without articles to be sterilized) at a pressure of about8×10² Pascals (Pa) to about 13.3×10² Pa and a temperature of about 45°C. to about 50° C. for a period of at least about 50 minutes, which aretypical conditions within an empty commercial hydrogen peroxide plasmasterilizer. More preferably, for use in conventional sterilizers, thehydrogen peroxide indicator compositions of the present inventionundergo a color change when exposed to an atmosphere containing about 6mg/l to about 7 mg/l hydrogen peroxide (in an empty chamber) at apressure of about 8×10² Pa to about 13.3×10² Pa and a temperature ofabout 45° C. to about 50° C. for a period of at least about 50 minutes.As used herein, a color change includes a change in color that isdetectable by the unaided eye, including becoming colorless.

[0036] The peracetic acid indicator compositions of the presentinvention preferably undergo a color change when exposed to liquidand/or vapor phase peracetic acid. Preferably, the peracetic acidindicators undergo a distinct color change when exposed to an atmospherecontaining at least 5% peracetic acid at room temperature for at least 5to 10 minutes. More preferably, the indicator compositions of thepresent invention undergo a color change when exposed to liquidperacetic acid at a concentration of between about 100 ppm to about10,000 ppm at temperatures between about 0° C. to about 100° C. forbetween about 1 second to about 15 minutes. As used herein, a colorchange includes a change in color that is detectable by the unaided eye,including becoming colorless.

[0037] Preferably, the indicator compositions do not significantly fadeupon exposure to room lighting, e.g., fluorescent lighting. Morepreferably, the indicator compositions do not significantly fade, forexample, upon exposure to sunlight through a window for one week or roomlighting for two months.

[0038] Colorants suitable for use in the indicator compositions of thepresent invention include colorants classified as Methane, Monoazo,Diazo, Triazo, Diazine, Cyanine, Thiazine, Xanthene, Oxazine,Anthraquinone, Benzodifuranone, Styryl, Phthalocyanine, Quinophthalone,Nitro, and Nitroso colorants, and combinations thereof, and/or colorantsincluding Victoria green S extra, Basic blue 41, Basic red 15, Acidgreen AX986, Keystone soap fluoro green, and Basic red 14 colorants, andcombinations thereof. Suitable colorants for use in the indicatorcompositions of the present invention further include Alphazurine A,Methyl violet 2B, Ethyl violet, FD/C blue 1, Brilliant blue R, Lissaminegreen B, Erioglaucine, Patent blue violet, Aniline blue, Victoria pureblue BO, Acid fuchsin sodium salt, Guinea green B, Alkali blue 4B,Coomassie violet R 150, Chromotrope 2B, D & C red No. 33, Bordeaux R,Acid violet 7, Acid violet 5, Plasmocorinth B, Cibacron brilliant red3B, Amaranth, Arsenazo 1, Acid blue 92, Eriochrome blue black B,Eriochrome black T, Mordant brown 48, Acid black 24, Acid red 97, Directred 75, Brilliant crocein MOO, Ponceau SS, Reactive black 5, Arsenazo111, Congo red, Acid blue 29, Acid blue 113, Acid red 151, Direct blue71, Azocarmine G, Methylene violet 3RAX, Toluidine blue O, Methylenegreen, Azure B, Sulforhodamine B, Rhodanine 6G, Violamine R, Nile blueA, Basic blue 3, Brilliant cresyl blue BB, Quinaldine red, Basic red 15,Alizarin violet 3R, Reactive blue 2, Victoria green S extra, Basic blue41, Acid green AX986, D & C green No. 5, Keystone soap fluoro green,Basic red 14, Brilliant black BN, Evans blue, Naphthol blue black,Xylidine ponceau 2R, Azocarmine B, and Fast green FCF. Alternative namesand Color Index Numbers for these colorants are listed in Tables 1-13below. Those colorants with classifications and/or Color Index Numbersthat are difficult to determine are indicated in the tables as “NotKnown.” In this instance, “Not Known” means merely that determination ofColorant Class and/or Color Index Number is difficult, not necessarilythat it is entirely unknown in the art. Various combinations of thesecolorants can be used in the indicator compositions of the presentinvention. Such mixtures or blends would increase the options availablein color changes dramatically.

[0039] For hydrogen peroxide indicators, suitable colorants becomecolorless or change to a different color, detectable by the unaided eye,upon exposure to hydrogen peroxide vapor under conventionalsterilization conditions (e.g., 6 mg/l to about 7 mg/l hydrogen peroxidein an empty chamber at a pressure of about 8×10² Pa to about 13.3×10² Paand a temperature of about 45° C. to about 50° C. for a period of atleast about 50 minutes) or to the more concentrated hydrogen peroxidevapors in a desiccator.

[0040] Preferably, at least one colorant is present in a hydrogenperoxide indicator composition in an amount sufficient to cause avisibly apparent color change when the composition is exposed to anatmosphere above an aqueous solution containing 30 wt-% hydrogenperoxide at 50° C. within a period of at least about one hour and/or anamount sufficient to cause a color change when exposed to an atmospherecontaining about 6 mg/l to about 7 mg/l hydrogen peroxide (in an emptychamber) at a pressure of about 8×10² Pa to about 13.3×10² Pa and atemperature of about 45° C. to about 50° C. for a period of at leastabout 50 minutes. Generally, the compositions contain about 0.1 wt-% toabout 5.0 wt-%, based on the total weight of the composition, of acolorant that changes color upon exposure to hydrogen peroxide.

[0041] In effect, the colorant concentration should be such as to allowa clear visual indication of a color change. Preferred are thosecolorants that show contrast between initial color and the color afterexposure to hydrogen peroxide vapor. Examples include hydrogen peroxideindicators including cupric chloride and Alphazurine A, Methyl violet2B, Ethyl violet, FD/C blue 1, Brilliant blue R, Lissamine green B,Erioglaucine, Victoria pure blue BO, Acid fuchsin sodium salt,Chromotrope 2B, D&C red No. 33, Bordeaux R, Acid violet 7, Acid violet5, Plasmocorinth B, Acid black 24, Acid red 97, Direct red 75, Brilliantcrocein MOO, Ponceau SS, Reactive black 5, Arsenazo 111, Direct blue 71,Azocarmine G, Methylene violet 3RAX, Toluidine blue O, Methylene green,Sulforhodamine B, Rhodanine 6G, Violamine R, Nile blue A, Basic blue 3,Brilliant cresyl blue BB, Quinaldine red, Basic red 15, Alizarin violet3R, Victoria green S extra, Basic blue 41, Acid green AX986, Keystonesoap fluoro green, Basic red 14, D & C green No. 5, and combinationsthereof (Tables 1b and 5); hydrogen peroxide indicators including cupricsulfate and Patent blue violet, Guinea green B, Methylene violet 3RAX,Azure B, Basic Red 15, Fast green FCF, and combinations thereof (Table6); and hydrogen peroxide indicators including cupric acetate andCoomassie violet R 150, Mordant brown 48, Acid red 151, Acid blue 29,Reactive blue 2, and combinations thereof (Table 10).

[0042] If at least one colorant that does not change color upon exposureto hydrogen peroxide is used in the indicator compositions of thepresent invention, it is present, alone or in combination with one ormore additional colorants, in an amount sufficient to provide thetargeted color intensity, both prior to and subsequent to exposure tohydrogen peroxide vapor. Generally, such compositions contain about 0.1wt-% to about 5.0 wt-%, based on the total weight of the composition, ofa colorant that does not change color upon exposure to hydrogenperoxide.

[0043] Such colorants that become substantially colorless after exposureto hydrogen peroxide acid can also be used in combination with othercolorants (e.g., dyes or pigments) that do not change color when exposedto hydrogen peroxide to give a chemical indicator with a suitablecontrasting color change by subtracting color. For example, an indicatorincluding the metal salt cupric chloride with Cibacron brilliant red 3B(pale pink, Table 1b, No. 15) and Ethyl violet (blue, Table 1b, No. 5)would have a blue green color, as a result of the mixture of pale pinkand blue. When exposed to hydrogen peroxide vapor, the Ethyl violetturns colorless (Table 1b, No. 5), leaving the pale pink of the Cibacronbrilliant red 3B, which does not change color when exposed to hydrogenperoxide vapor (Table 1b, No. 15).

[0044] Preferred are those colorants that have an initial color andturns colorless after exposure to hydrogen peroxide vapor. Examplesinclude hydrogen peroxide indicators including ferrous chloride andAlphazurine A, Methyl violet 2B, Ethyl violet, FD/C blue 1, Brilliantblue R, Lissamine green B, Erioglaucine, Victoria pure blue BO, Acidfuchsin sodium salt, Cibacron brilliant red 3B, Chromotrope 2B, D&C redNo. 33, Acid violet 7, Acid violet 5, Plasmocorinth B, Acid black 24,Acid red 97, Direct red 75, Brilliant crocein MOO, Ponceau SS, Reactiveblack 5, Arsenazo 111, Azocarmine G, Methylene violet 3RAX, Toluidineblue O, Methylene green, Sulforhodamine B, Rhodanine 6G, Violamine R,Nile blue A, Basic blue 3, Brilliant cresyl blue BB, Basic red 15,Alizarin violet 3R, Victoria green S extra, Basic blue 41, Acid greenAX986, Keystone soap fluoro green, Basic red 14, D & C green No. 5, andcombinations thereof (Tables 2 and 7); hydrogen peroxide indicatorsincluding ferrous sulfate and Eriochrome black T, Eriochrome blue blackB, Acid blue 113, Acid red 151, and combinations thereof (Table 8);hydrogen peroxide indicators including cupric chloride and AlphazurineA, Methyl violet 2B, Ethyl violet, FD/C blue 1, Brilliant blue R,Lissamine green B, Erioglaucine, Victoria pure blue BO, Acid fuchsinsodium salt, Acid violet 5, Plasmocorinth B, Acid black 24, Acid red 97,Direct red 75, Arsenazo 111, Azocarmine G, Methylene violet 3RAX,Toluidine blue O, Methylene green, Rhodanine 6G, Basic blue 3, Brilliantcresyl blue BB, Quinaldine red, Basic red 15, Victoria green S extra,Basic blue 41, Keystone soap fluoro green, Basic red 14, D & C green No.5, and combinations thereof (Tables 1b and 5); hydrogen peroxideindicators including cobalt chloride and Patent blue violet, Anilineblue, Arsenazo 1, Acid blue 92, Congo red, Acid blue 29, andcombinations thereof (Table 3b); hydrogen peroxide indicators includingcobalt acetate and Erioglaucine, Eriochrome blue black B, Nile blue A,Reactive blue 2, Basic red 15, D&C green No. 5, and combinations thereof(Table 4); hydrogen peroxide indicators including cupric sulfate andMethylene violet 3RAX (Table 6); hydrogen peroxide indicators includingchromium potassium sulfate and Ethyl violet, Eriochrome black T,Eriochrome blue black B, Acid blue 113, Quinaldine red, and combinationsthereof (Table 9); and hydrogen peroxide indicators including cupricacetate and Coomassie violet R 150 (Table 10).

[0045] For peracetic acid indicators, suitable colorants change to adifferent color upon exposure to liquid peracetic acid underconventional sterilization conditions. The peracetic acid indicatorcompositions of the present invention preferably undergo a color changewhen exposed to liquid and/or vapor phase peracetic acid. Preferably,the peracetic acid indicators undergo a distinct color change whenexposed to an atmosphere containing at least 5% peracetic acid at roomtemperature for at least 5 to 10 minutes. More preferably, the indicatorcompositions of the present invention undergo a color change whenexposed to liquid peracetic acid at a concentration of between about 100ppm to about 10,000 ppm at temperatures between about 0° C. to about100° C. for between about 1 second to about 15 minutes.

[0046] Preferably, at least one colorant is present in a peracetic acidindicator composition in an amount sufficient to cause a visiblyapparent color change when the composition is exposed in a sterilizationchamber to a sterilant including liquid peracetic acid at aconcentration of 0.2 percent and a pH of 6.4 for about 12 minutes at atemperature of between about 50° C. to about 56° C. The colorantconcentration should be such as to allow a clear visual indication of acolor change detectable by the unaided eye. Preferred colorants forperacetic acid indicators are those colorants that show contrast betweenthe initial color and the color after exposure to liquid peracetic acidvapor. Examples include peracetic acid indicators including cupricacetate and Evans blue, Acid violet 7, Naphthol blue black, Reactiveblack 5, Brilliant black BN, Azocarmine B, and combinations thereof(Table 11); peracetic acid indicators including cobalt acetate andCibacron brilliant red 3B, Evans blue, Reactive black 5, Brilliant blackBN, and combinations thereof (Table 12); and peracetic acid indicatorsincluding cupric sulfate and Evans blue, Acid violet 7, Naphthol blueblack, Reactive black 5, Brilliant black BN, Azocarmine B, andcombinations thereof (Table 13).

[0047] Preferably, hydrogen peroxide indicators and peracetic acidindicators of the present invention include a metal salt. Preferably themetal salt is a transition metal salt. More preferably, the metal saltincludes one or more metals from Groups VIB, VIII, and IB of thePeriodic Chart, which include iron, copper, cobalt, and chromium. Evenmore preferably, the metal salt includes metals from Groups VIII and IBof the Periodic Chart, which include iron, copper, cobalt, andcombinations thereof. Most preferably, the metal salt includes ironand/or copper.

[0048] The salts can include inorganic or organic anions. Examplesinclude chloride, acetate, sulfate, chromate, iodate, molybdate,nitrate, oxalate, citrate, propionate, lactate, malate, tartrate, andbenzoate. Preferred anions include chloride, acetate, and sulfate.

[0049] The indicator composition is generally formulated in the form ofa dispersion or solution in water or an organic solvent (preferably, anorganic solvent). The composition includes at least one colorant asdescribed above as well as an organic binder resins. A wide variety ofsuitable binder resins can be used. Examples include synthetic ornatural polymers or resins. Suitable binder resins are those that do notinterfere with the function of the indicator composition. Examplesinclude cellulose acetate butyrate, cellulose acetate propionate,hydroxypropyl cellulose, nitrocellulose, urethane alkyd, epoxy,alkylated urea- and melamine-formaldehyde, polyamide, styrene butadiene,vinyl, phenolic, shellac, ethyl cellulose, methyl cellulose, acrylic,and ultraviolet and electron beam curable resins. A sufficient amount ofbinder resin is included in the compositions to provide adequate bindingof the composition to a substrate on which it is disposed, whileproviding the desired rate of color change. Generally, the compositionscontain about 20 wt-% to about 40 wt-% of a polymer binder resin, basedon the total weight of the composition.

[0050] Indicator compositions of the present invention can also includeother resins that do not necessarily function as a binder resin. Forexample, the compositions can include a resin that functions as adispersing agent, such as Rhoplex I-545, a water based acrylic polymer,available from Rohm and Haas Corp., Philadelphia, Pa., that assists indispersing the ingredients of the composition in the solvent used inapplication of the composition to a substrate. Indicator compositions ofthe present invention can also include opacifying agents such astitanium dioxide, surfactants, plasticizers, antifoam agents, and thelike. For certain embodiments, a basic material such as an organic amine(e.g., triethanolamine) can be used to enhance sensitivity of thecolorant to the low concentration of hydrogen peroxide in a conventionalsterilizer. Typically, such additives are used in no more than about 5wt-% based on the total weight of the indicator composition.

[0051] The compositions are typically applied to a substrate out of asolvent as discussed above. Suitable solvents include water and organicsolvents such as ketones, esters, alcohols, and the like. Examples ofsuitable solvents include methyl ethyl ketone, n-propyl acetate, andisopropanol. The solvent is typically used in an amount of up to about20 wt-%, based on the total weight of the composition. The indicatorcomposition can be applied to the substrate by a wide variety oftechniques, including, for example, printing or coating by flexographic,gravure, screen, or die processes.

[0052] The substrate on which the indicator composition is disposed canbe any of a wide variety. Typically, suitable substrates includepolymeric materials, which may be pigmented or colorless, such aspolyester, polyethylene, or polystyrene films, nonwovens, paper, and thelike. Preferably, it is a plastic polystyrene backing (commerciallyavailable from Plastic Suppliers, Inc., Chicago Heights, Ill.). Thesubstrate may be in the form of a strip of material (e.g., a strip ofmaterial having the dimensions 2 cm by 13 cm). Optionally, thecomposition can be coated as a stripe over the length of the substratestrip. The substrate may also have an adhesive on the surface oppositethat on which the indicator composition is disposed. In this way, theindicator may be used as a tape or label for attachment to the articleto be sterilized.

[0053] The hydrogen peroxide vapor sterilization procedure used isconventional, and is disclosed in, for example, U.S. Pat. Nos.4,756,882, 4,643,876, 4,956,145, and 5,445,792. Preferably, it is aplasma-based sterilization system.

[0054] In general, the article to be sterilized is placed in asterilization chamber with any of the preferred embodiments of hydrogenperoxide indicator of the invention, and a dose of hydrogen peroxide,which generally comes pre-measured, is delivered to the chamber. Vaporis generated and allowed to fill the container for an appropriate lengthof time after which the sterilization is complete. The indicator is theninspected for color change. The equipment and the entire proceduregenerally are controlled electronically. When sterilizing medicalinstruments, one cycle is often sufficient. The medical instruments areoften packaged, with the entire package being placed into thesterilizing compartment. The package allows the hydrogen peroxide topenetrate and effect sterilization of the instruments, whilesubsequently protecting the instruments from contamination in air. Thetemperatures used in the process of the present invention are allgenerally less than 65° C.

[0055] The peracetic acid sterilization procedures that may be used areconventional, and are disclosed in, for example, U.S. Pat. Nos.6,287,518 and 4,892,706. A conventional liquid peracetic acidsterilization procedure is disclosed in U.S. Pat. No. 4,892,706.

[0056] In general, the article to be sterilized is placed in asterilization chamber with any of the preferred embodiments of peraceticacid indicator of the invention. Concentrated peracetic acid is thendiluted in a buffer solution to form a sterilant solution, which isintroduced to and circulated throughout the sterilization chamber. Thearticle to be sterilized and the indicator are exposed to the sterilantsolution for at least approximately 12 minutes at a temperature at orbelow about 60° C. The sterilization chamber is then drained and rinsedwith water. The rinsed article and indicator are removed from thesterilization chamber and the indicator is inspected for color change.

[0057] The invention will be illustrated in greater detail by thefollowing specific examples. It is understood that these examples aregiven by way of illustration and are not meant to limit the disclosureor the claims to follow. All percentages in the examples, and elsewherein the specification, are by weight unless otherwise specified.

EXAMPLES Control Example a Without Metal Salts

[0058] Control indicator compositions (Control Indicator Composition A)were prepared by shaking 10 milliliters (ml) of a binder-solutioncontaining 7 wt-% percent of hydroxypropyl cellulose in 9 partsmethanol: 1 part water, with approximately 0.1 gram (g) or a sufficientamount of colorant (0.1 wt-% to 5 wt-%) to give a good color in a glassvial. The colorants used to prepare these control indicator compositionsare listed in Table 1a.

Example 1 Preparation of Indicator Compositions

[0059] Indicator compositions (Indicator Composition 1) listed in Table1b were prepared by adding 1 drop of a saturated cupric chloride watersolution to the control indicator compositions described in ControlExample A and shaking in the glass vial.

Coating of Indicator Compositions

[0060] Indicator compositions and control indicator compositions werecoated on plastic polystyrene backing (commercially available fromPlastic Suppliers Inc., Chicago Heights, Ill.) using a number 16 Meyerbar (commercially available from R. D. Specialties, Webster, N.Y.). Thecoated inks were dried at 50° C. in an oven (commercially available as“Despatch Style V 29” from Despatch Oven Co., Minneapolis, Minn.) for 2minutes. The coated films were cut using scissors to obtain indicatorsapproximately 2 centimeters (cm) by 13 cm.

Test Method

[0061] Each coated indicator composition and coated control indicatorcomposition was placed on an instrument tray lid and exposed to a fullHospital 100 cycle of a hydrogen peroxide plasma sterilization procedureat 45-55° C. in a STERRAD 100SI GMP Sterilizer, obtained from AdvancedSterilization Products Co., Irvine, Calif. During the sterilizationprocedure a vacuum was drawn in the sterilization chamber for 5-6minutes until the pressure was reduced to 40.0 Pa. A 1.8 ml aliquot ofan aqueous solution of 58-60 percent hydrogen peroxide was then injectedinto the empty sterilization chamber, yielding an empty chamberconcentration of 6-7 mg/l hydrogen peroxide. Hydrogen peroxide vapor wasallowed to diffuse throughout the chamber for 44 minutes at 8×10² to13.3×10² Pa. A vacuum was then drawn, reducing the pressure to 66.7 Paand removing all detectable hydrogen peroxide vapor from the chamber. Aplasma phase was then generated in the chamber by emitting an RF powersource at 400 watts and 13.56 MegaHertz (MHz) for about 15-16 minutes at66.7 Pa, after which the chamber was vented for 3-4 minutes untilatmospheric pressure was reached in the chamber. After exposure to thesterilization procedure the indicators were removed from the tray lidand examined for color change. The results for each control indicatorcomposition and indicator composition are described in Table la andTable 1b, respectively.

[0062] After the colorants were exposed to a full Hospital 100 cycle ofhydrogen peroxide plasma sterilization procedure as described above,most of the control indicator compositions (Table 1a) did not changefrom their initial color. However, Victoria green S extra becamecolorless; Basic blue 41, Toluidine blue O, and Arsenazo 111 becamelighter; Quinaldine red and Alkali blue 4B became slightly lighter; andViolamine R changed from a light pink to pink/violet (darker).

[0063] After cupric chloride was added to the indicator composition,most of the colorants either became colorless or significantly lighterwhen exposed to hydrogen peroxide plasma as described above (Table 1b).The colorants including cupric chloride that did not change or changedso slightly as to make the change difficult to see with the human eyewere Cibacron brilliant red 3B, Amaranth, and Brilliant black BN; Nileblue A changed from light blue to light gray; Bordeaux R changed fromlight pink to a slightly lighter pink; Direct red 75 changed from almostcolorless to colorless; and Ponceau SS changed from pink/beige to lightpurple/pink.

[0064] As demonstrated in Example 2, below (Table 2), the choice ofmetal ion can affect the color change. For instance an indicatorcomposition including one metal ion can produce a color change in anindicator composition exposed to a sterilant that is different from thatof an indicator composition including the same colorant with a differentmetal ion that is also exposed to a sterilant. Compare, for example, thecolorant Chromotrope 2B listed in Table 2, No. 7 (with ferrous chloride)that turns colorless with Chromotrope 2B listed in Table 1b, No. 57(with cupric chloride) that turns beige.

Example 2 Preparations of Indicator Compositions Using Ferrous Chloride

[0065] Indicator compositions (Indicator Composition 2, Table 2) wereprepared by adding 1 drop of a saturated ferrous chloride water solutionto the control indicator compositions described in Control Example A andshaking in the glass vial. The colorants used with the ferrous chlorideare listed in Table 2.

[0066] Indicator compositions and control indicator compositions werecoated on plastic backings and sterilized as described in Example 1.

[0067] The results for each control indicator composition (ControlIndicator Composition A) and Indicator Composition 2 are shown in Table1 a and Table 2, respectively.

[0068] After the addition of ferrous chloride to the controlcomposition, each of the colorants listed in Table 2 either becamecolorless or significantly lighter when exposed to hydrogen peroxideplasma as described above.

Control Example B Without Metal Salts

[0069] Control indicator compositions (Control Indicator B, Table 3a)were prepared by shaking 10 milliliters (ml) of a binder solutioncontaining 5 wt-% of hydroxypropyl cellulose in 6 parts methanol: 4parts water, with approximately 0.1 g or a sufficient amount of colorant(0.1 wt-% to 5 wt-%) to give a good color in a glass vial. The colorantsused in the Control Indicator Composition B for Examples 3-10 are listedin Table 3a.

Example 3 Preparation of Indicator Compositions Using Cobalt Chloride

[0070] A drop of cobalt chloride salt solution containing 1 g of salt to3.25 g of water was added to the control indicator composition describedin Control Example B and shaken in a glass vial. The colorants used withcobalt chloride are listed in Table 3b.

[0071] Indicator compositions and control indicator compositions werecoated on plastic backings and sterilized as described in Example 1.

[0072] The results for each Control Indicator Composition B andIndicator Composition 3 are shown in Table 3a and Table 3b respectively.

[0073] After the colorants were exposed to a full Hospital 100 cycle ofhydrogen peroxide plasma sterilization procedure as described above,most of the colorants did not change from their initial color. However,Guinea green B became almost colorless; Acid fuchsin sodium salt becamelighter; Nile blue A, Arsenazo 1, Basic red 14, Basic red 15, and Alkaliblue 4B became slightly lighter; Azure B became significantly lighter,Aniline blue changed from blue to gray/green; Quinaldine red changedfrom muddy pink to light pink, and Acid blue 92 changed from lilac tolight violet.

[0074] After the addition of cobalt chloride to the control composition,all of the colorants listed in Table 3b became colorless when exposed tohydrogen peroxide plasma as described above.

Example 4 Preparation of Indicator Compositions Using Cobalt Acetate

[0075] Indicator compositions were prepared as described in Example 3except a drop of cobalt acetate salt solution containing 1 g of salt to3.25 g of water was added to the initial composition and shaken in aglass vial. The colorants used are listed in Table 4

[0076] Indicator compositions and control indicator compositions werecoated on plastic backings and sterilized as described in Example 1.

[0077] The results for each control indicator composition and IndicatorComposition 4 are shown in Table 3a and Table 4, respectively.

[0078] After the addition of cobalt acetate to the control compositioneach of the colorants listed in Table 4 became colorless when exposed tohydrogen peroxide plasma as described above.

Example 5 Preparation of Indicator Compositions Using Cupric Chloride

[0079] Indicator compositions were prepared as described in Example 3except four drops of cupric chloride salt solution containing 1 g ofsalt to 13 g of water was added to the initial composition and shaken ina glass vial. The colorants used are listed in Table 5

[0080] Indicator compositions and control indicator compositions werecoated on plastic backings and sterilized as described in Example 1.

[0081] The results for each control indicator composition and IndicatorComposition 5 are shown in Table 3a and Table 5, respectively.

[0082] After the addition of cupric chloride to the control composition,each of the colorants listed in Table 5 became colorless when exposed tohydrogen peroxide plasma as described above.

Example 6 Preparation of Indicator Compositions Using Cupric Sulfate

[0083] Indicator compositions were prepared as described in Example 3except four drops of cupric sulfate salt solution containing 1 g of saltto 13 g of water was added to the initial composition and shaken in aglass vial. The colorants used are listed in Table 6

[0084] Indicator compositions and control indicator compositions werecoated on plastic backings and sterilized as described in Example 1.

[0085] The results for each control indicator composition and IndicatorComposition 6 are shown in Table 3a and Table 6, respectively.

[0086] The addition of cupric sulfate to the control composition of thecolorants listed in Table 6 did not show as dramatic results as thepreceding examples. Each colorant changed color when exposed to hydrogenperoxide plasma as described above; however, Azure B became clear,Methylene violet 3RAX became almost colorless, and Basic red 15 becamesignificantly lighter. Patent blue violet changed from green/blue togreen/gray; Guinea green B and Fast green FCF changed from green to amottled green on clear when exposed to hydrogen peroxide plasma.

Example 7 Preparation of Indicator Compositions Using Ferrous Chloride

[0087] Indicator compositions were prepared as described in Example 3except a drop of ferrous chloride salt solution containing 1 g of saltto 3.25 g of water was added to the initial composition and shaken in aglass vial. The colorants used are listed in Table 7.

[0088] Indicator compositions and control indicator compositions werecoated on plastic backings and sterilized as described in Example 1.

[0089] The results for each control indicator composition and IndicatorComposition 7 are shown in Table 3a and Table 7, respectively.

[0090] After the addition of ferrous chloride to the controlcomposition, the colorants listed in Table 7 became colorless whenexposed to hydrogen peroxide plasma as described above.

Example 8 Preparation of Indicator Compositions Using Ferrous Sulfate

[0091] Indicator compositions were prepared as described in Example 3except four drops of ferrous sulfate salt solution containing 1 g ofsalt to 13 g of water was added to the initial composition and shaken ina glass vial. The colorants used are listed in Table 8

[0092] Indicator compositions and control indicator compositions werecoated on plastic backings and sterilized as described in Example 1.

[0093] The results for each control indicator composition and IndicatorComposition 8 are shown in Table 3a and Table 8, respectively.

[0094] After the addition of ferrous sulfate to the control composition,each of the colorants either became colorless, almost colorless, orsignificantly lighter when exposed to hydrogen peroxide plasma asdescribed above.

Example 9 Preparation of Indicator Compositions Using Chromium PotassiumSulfate

[0095] Indicator compositions were prepared as described in Example 3except a drop of chromium potassium sulfate salt solution containing 1 gof salt to 3.25 g of water was added to the initial composition andshaken in a glass vial. The colorants used are listed in Table 9.Indicator compositions and control indicator compositions were coated onplastic backings and sterilized as described in Example

[0096] The results for each control indicator composition and IndicatorComposition 9 are shown in Table 3a and Table 9, respectively.

[0097] After the addition of chromium potassium sulfate to the controlcomposition, each of the colorants except Congo red became colorlesswhen exposed to hydrogen peroxide plasma as described above. Congo redchanged from red to brown, which is a significant change to be seen bythe human eye.

Example 10 Preparation of Indicator Compositions Using Cupric Acetate

[0098] Indicator compositions were prepared as described in Example 3except a drop of cupric acetate salt solution containing 1 g of salt to3.25 g of water was added to the initial composition and shaken in aglass vial. The colorants used are listed in Table 10.

[0099] Indicator compositions and control indicator compositions werecoated on plastic backings and sterilized as described in Example 1.

[0100] The results for each control indicator composition B andIndicator Composition 10 are shown in Table 3a and Table 10,respectively.

[0101] After the addition of cupric acetate to the control composition,the colorants listed in Table 10 became almost colorless, significantlylighter, or lighter except Xylidine ponceau 2R when exposed to hydrogenperoxide plasma as described above. Xylidine ponceau 2R did not changecolor with the addition of cupric acetate and exposure to hydrogenperoxide plasma.

Example 11 Preparation of Indicator Compositions with Cupric Acetate andDevice

[0102] Indicator compositions were prepared by dissolving 0.3 g ofcolorant in 90 ml of water. The colorants are listed in Table 11. Theresulting solution was divided equally into 3 boats. A control indicatorwas made by immersing an 11 cm circle of Whatman Grade 1 filter paper inthe solution, allowing the excess solution to drip from the paper, anddrying for approximately 1 hour. The color of the dried control isrecorded in Table 11.

[0103] A second solution (Indicator Composition 11) was prepared byadding 1.0 g of a cupric acetate {Cu(C₂H₃O₂)₂—H₂O} (available fromMallinckrodt, Inc., Hazelwood, Mo.) to 13 ml of water.

[0104] Five ml of the second solution was added to the solution in eachboat. Three more 11 cm circles of filter paper were immersed one in eachboat, allowed to drip and dried like the control. The color of the driedcolorant and metallic salt composition is recorded in Table 11.

[0105] Adhesive (3M VHB acrylate adhesive on a release liner) wasapplied by transfer of the adhesive from the release liner to one sideof each dried filter paper. A 1.9 cm (0.75 inch) circle was cut from theadhesive backed filter paper. The smaller adhesive circle was applied tothe center of a 5.08 cm square (2 inch) by 0.25 millimeter (0.01 inch)thick piece of TYVEK type 10 1025 D spunbond olefin backing, availablefrom E. I. du Pont de Nemours and Company, Wilmington, Del. The circlewas enclosed within a device in the following manner. A 5.08 cm (2 inch)square by 0.25 mm (0.01 inch) thick piece of polyvinyl chloride(available as PJN-9708623 from Perfecseal, Minneapolis, Minn.) having acentral 2.54 cm (1 inch) square by 0.95 cm (⅜ inch) deep vapor headspace was glued using, Loctite 411 instant adhesive, to the spunbondbacking.

Test Method

[0106] The devices were processed in the STERIS SYSTEM 1 sterilizer,obtained from STERIS Corporation, Mentor, Ohio. The devices were sealedin the sterilizer and exposed to a preliminary wash with ananticorrosive buffer solution. Sixty (60) ml of 35 percent liquidperacetic acid was then introduced to the buffer solution and circulatedthroughout the sterilization chamber for 12 minutes at 50-56° C. Thecirculating sterilant had a liquid peracetic acid concentration of 0.2percent and a pH of 6.4. The sterilant was then drained and thesterilizing chamber was washed with water four times. The devices wereremoved and examined visually for color changes. The results arerecorded in Table 11. Some of the devices changed color on the edges ofthe circle, but retained the initial color in the center. New indicatordevices were tested without applying an adhesive coating to the back ofthe colored filter paper. The results of Examples 11-13 are noted inTables 11, 12, and 13.

Example 12 Preparation of Indicator Compositions with Copper Sulfate andDevices

[0107] Indicator compositions were prepared as for Example 11. Thecolorants used are listed in Table 12. The second solution (IndicatorComposition 12) was prepared by adding 1.0 g of copper sulfate(CuSO₄.5H₂O) (available from Mallinckrodt, Inc., Hazelwood, Mo.) to 13ml of water. Devices were prepared and tested as described in Example11. The results are recorded in Table 12.

Example 13 Preparation of Indicator Compositions with Cobalt Acetate andDevices

[0108] Indicator compositions were prepared as for Example 11. Thecolorants used are listed in Table 13. The second solution (IndicatorComposition 13) was prepared by adding 1.0 g of cobalt(II) acetatetetrahydrate {Co(C₂H₃O₂)₂.4H₂O} (available from Sigma-Aldrich FineChemicals, St. Louis, Mo.) to 13 ml of water. Devices were prepared andtested as described in Example 11. The results are recorded in Table 13.TABLE 1a Control Indicator Composition A Colorants and Results afterSterilization Color Index Initial Color without Metallic Color Change inNo. Colorant Colorant Class Number Salts Sterilizer 1 ¹Alphazurine AMethane 42080 Blue/green None 2 ¹Azocarmine G Diazine 50085 Purple/pinkNone 3 Victoria green S extra Not known Not known Green Colorless 4¹Methyl violet 2B Methane 42535 Purple None (Basic violet 1) 5 ¹Ethylviolet (Basic Methane 42600 Blue None violet 4) 6 ¹Alizarin violet 3RAnthraquinone 61710 Light lilac None 7 ¹Basic blue 41 Not known Notknown Dark lilac Lighter 8 ⁴FD/C blue 1 Methane 42090 Light blue None 9¹Toluidine blue O Thiazine 52040 Violet Lighter (Basic blue 17 orTolonium chloride) 10 ¹Nile blue A Oxazine 51180 Purple/blue None 11¹Quinaldine red Cyanine None Red/gray Slightly lighter 12 ¹Basic blue 3Oxazine 51004 Blue/green None 13 ¹Acid black 24 Diazo 26370 Blue/blackNone 14 ¹Acid red 97 Diazo 22890 Orange None 15 ¹Cibacron brilliant redMonoazo Not known Pale pink None 3B 16 ¹Sulforhodamine B Xanthene 45100Hot pink None 17 ¹Direct blue 71 Triazo 34140 Purple/black None 18¹Chromotrope 2B Monoazo 16575 Pink-beige None 19 ¹Brilliant blue R (AcidMethane 42660 Blue None blue 83 or Coomassie brilliant blue R) 20¹Amaranth Monoazo 16185 Pink/gray None 21 ¹Rhodanine 6G Xanthene 45160Hot pink None 22 ⁵Brilliant cresyl blue Oxazine 51010 Blue None BB 23 ³D& C red No. 33 Monoazo 17200 Red lilac 24 ¹Bordeaux R Monoazo 16180Light pink None 25 ¹Direct red 75 Diazo 25380 Pale pink None 26 ¹Acidviolet 7 Monoazo 18055 Lilac None 27 ¹Acid violet 5 Monoazo 18125 Darkpink None 28 ¹Plasmocorinth B Monoazo 16680 Dark pink None 29 ¹Brilliantcrocein Diazo 27290 Orange None MOO 30 ¹Methylene green Thiazine 52020Pale blue/gray Pale pink/gray 31 ¹Methylene violet Diazine 50206 PinkNone 3RAX 32 ¹Ponceau SS Diazo 27190 Pink/beige None 33 ¹Reactive black5 Diazo 20505 Blue/black None 34 ²Basic red 15 Not known Not known Hotpink None 35 ³Acid green AX986 Not known Not known Lime green None 36¹Lissamine green B Methane 44090 Blue/green None (Acid Green 50 or WoolGreen S) 37 ¹Erioglaucine Methane 42090 Blue/green None 38 ¹Violamine RXanthene 45190 Light pink Pink/violet 39 ¹Brilliant black BN Diazo 28440Dark gray None 40 ¹Arsenazo 111 Diazo None Dark lilac Lighter 41 ³Alkaliblue 4B Methane 42750 Blue Slightly lighter 42 ³Coomassie violet RMethane 42650 Grey/blue None 150 43 ¹Acid blue 92 Monoazo 13390 LilacLight violet 44 ¹Acid blue 29 Diazo 20460 Grey/blue None 45 ¹Xylidineponceau 2R Monoazo 16150 Orange None 46 ¹Reactive blue 2 Anthraquinone61211 Blue/gray None

[0109] TABLE 1b Indicator Composition 1 Colorants and Results afterSterilization Color Index Initial Color with Color Change in No.Colorant Colorant Class Number Color Cupric Chloride Sterilizer 1¹Alphazurine A Methane 42080 Blue/green Blue/green Almost colorless 2¹Azocarmine G Diazine 50085 Purple/pink Purple/pink Significantlylighter 3 Victoria green S Not known Not known Green Green Colorlessextra 4 ¹Methyl violet 2B Methane 42535 Purple Purple Colorless (Basicviolet 1) 5 ¹Ethyl violet (Basic Methane 42600 Blue Blue Colorlessviolet 4) 6 ¹Alizarin violet 3R Anthraquinone 61710 Light lilac Lightlilac Lighter 7 ¹Basic blue 41 Not known Not known Dark lilac Dark lilacColorless 8 ⁴FD/C blue 1 Methane 42090 Light blue Light blue Almostcolorless 9 ¹Toluidine blue O Thiazine 52040 Violet Blue/gray Colorless(Basic blue 17 or Tolonium chloride) 10 ¹Nile blue A Oxazine 51180Purple/blue Very Light blue, Light gray Almost Colorless 11 ¹Quinaldinered Cyanine None Red/gray Pale pink/gray Colorless 12 ¹Basic blue 3Oxazine 51004 Blue/green Blue Colorless 13 ¹Acid black 24 Diazo 26370Blue/black Blue/black Colorless 14 ¹Acid red 97 Diazo 22890 OrangeOrange Colorless 15 ¹Cibacron brilliant Monoazo Not known Pale pink Palepink No change red 3B 16 ¹Sulforhodamine B Xanthene 45100 Hot pink Hotpink Very light pink 17 ¹Direct blue 71 Triazo 34140 Purple/blackPurple/black Slightly lighter 18 ¹Chromotrope 2B Monoazo 16575Pink-beige Dark gray Beige 19 ¹Brilliant blue R Methane 42660 Blue BlueColorless (Acid blue 83 or Coomassie brilliant blue R) 20 ¹AmaranthMonoazo 16185 Pink/gray Pink/gray No change 21 ¹Rhodanine 6G Xanthene45160 Hot pink Hot pink Almost colorless 22 ⁵Brilliant cresyl Oxazine51010 Blue Blue Colorless blue BB 23 ³D & C red No. 33 Monoazo 17200 RedPurple/pink Tan 24 ¹Bordeaux R Monoazo 16180 Light pink Light pinkSlightly lighter 25 ¹Direct red 75 Diazo 25380 Pale pink AlmostColorless colorless 26 ¹Acid violet 7 Monoazo 18055 Lilac Lilac Verylight lilac 27 ¹Acid violet 5 Monoazo 18125 Dark pink Light redColorless 28 ¹Plasmocorinth B Monoazo 16680 Dark pink Light violetColorless 29 ¹Brilliant crocein Diazo 27290 Orange Light red Very paleorange MOO 30 ¹Methylene green Thiazine 52020 Pale Pale blue/grayColorless blue/gray 31 ¹Methylene violet Diazine 50206 Pink PinkColorless 3RAX 32 ¹Ponceau SS Diazo 27910 Pink/beige Pink/beige Lightpurple/pink 33 ¹Reactive black 5 Diazo 20505 Blue/black Blue/black Beige34 ³Basic red 15 Not known Not known Hot pink Hot pink Colorless 35²Acid green AX986 Not known Not known Lime green Lime green Tan 36¹Lissamine green B Methane 44090 Blue/green Blue/green Colorless (AcidGreen 50 or Wool Green S) 37 ¹Erioglaucine Methane 42090 Blue/greenBlue/green Colorless 38 ¹Violamine R Xanthene 45190 Light pinkPink/violet Very light pink 39 ¹Brilliant black BN Diazo 28440 Dark grayDark gray No change 40 ¹Arsenazo 111 Diazo None Dark lilac Blue/blackAlmost colorless

[0110] TABLE 2 Indicator Composition 2 Colorants and Results afterSterilization Color Index Color with Ferrous Color Change in No.Colorant Colorant Class Number Initial Color Chloride Sterilizer 1¹Alphazurine A Methane 42080 Blue/green Blue/green Colorless 2¹Azocarmine G Diazine 50085 Purple/pink Purple/pink Colorless 3 Victoriagreen S Not known Not known Green Green Colorless extra 4 ¹Methyl violet2B Methane 42535 Purple Purple Colorless (Basic violet 1) 5 ¹Ethylviolet Methane 42600 Blue Blue Colorless (Basic violet 4) 6 ¹Alizarinviolet 3R Anthraquinone 61710 Light lilac Light lilac Colorless 7 ¹Basicblue 41 Not known Not known Dark lilac Dark lilac Colorless 8 ⁴FD/C blue1 Methane 42090 Light blue Light blue Colorless 9 ¹Toluidine blue OThiazine 52040 Violet Blue/gray Colorless 10 ¹Nile blue A Oxazine 51180Purple/blue Blue/green Colorless 11 ¹Quinaldine red Cyanine NoneRed/gray Pink/gray Colorless 12 ¹Basic blue 3 Oxazine 51004 Blue/greenBlue/green Colorless 13 ¹Acid black 24 Diazo 26370 Blue/black Blue/blackColorless 14 ¹Acid red 97 Diazo 22890 Orange Orange Colorless 15¹Cibacron brilliant Monoazo Not known Pale pink Pale pink Colorless red3B 16 ¹Sulforhodamine B Xanthene 45100 Hot pink Hot pink Colorless 17¹Direct blue 71 Triazo 34140 Purple/black Purple/black Significantlylighter 18 ¹Chromotrope 2B Monoazo 16575 Pink-beige Pink-beige Colorless19 ¹Brilliant blue R Methane 42660 Blue Blue Colorless (Acid blue 83 orCoomassie brilliant blue R) 20 ¹Amaranth Monoazo 16185 Pink/grayPink/gray Significantly lighter 21 ¹Rhodanine 6G Xanthene 45160 Hot pinkHot pink Colorless 22 ⁵Brilliant cresyl Oxazine 51010 Blue BlueColorless blue BB 23 ³D & C red No. 33 Monoazo 17200 Red Red Colorless24 ¹Bordeaux R Monoazo 16180 Light pink Light pink Significantly lighter25 ¹Direct red 75 Diazo 25380 Pale pink Pale pink Colorless 26 ¹Acidviolet 7 Monoazo 18055 Lilac Lilac Colorless 27 ¹Acid violet 5 Monoazo18125 Dark pink Dark pink Colorless 28 ¹Plasmocorinth B Monoazo 16680Dark pink Brown Colorless 29 ¹Brilliant crocein Diazo 27290 OrangeOrange Colorless MOO 30 ¹Methylene green Thiazine 52020 Pale blue/grayPale blue/gray Colorless 31 ¹Methylene violet Diazine 50206 Pink PinkColorless 3RAX 32 ¹Ponceau SS Diazo 27190 Pink/beige Pink/beigeColorless 33 ¹Reactive black 5 Diazo 20505 Blue/black Blue/blackColorless 34 ²Basic red 15 Not known Not known Hot pink Hot pinkColorless 35 ³Acid green Not known Not known Lime green Lime greenColorless AX986 36 ¹Lissamine green Methane 44090 Blue/green Blue/greenColorless B (Acid Green 50 or Wool Green S) 37 ¹Erioglaucine Methane42090 Blue/green Blue/green Colorless 38 ¹Violamine R Xanthene 45190Light pink Pink/Violet Colorless 39 ¹Brilliant black BN Diazo 28440 Darkgray Dark gray Colorless 40 ¹Arsenazo 111 Diazo None Dark lilac Darkgray Colorless

[0111] TABLE 3a Control Indicator B Colorants and Results afterSterilization Color Index Initial Color without Color Change in No.Colorant Colorant Class Number Metallic Salts Sterilizer 1 ¹Azocarmine GDiazine 50085 Purple/pink None 2 ¹Ethyl violet (Basic Methane 42600 Darkpurple/blue None violet 4) 3 ¹Victoria pure blue Methane 42595 Blue NoneBO (Basic blue 7) 4 ¹Nile blue A Oxazine 51180 Lilac Slightly lighter 5¹Quinaldine red Cyanine None Muddy pink Light pink 6 ³Patent blue violetMethane None Green/blue None 7 ¹Acid fuchsin Methane 42685 Hot pinkLighter sodium salt 8 ¹Eriochrome black T Monoazo 14645 Light muddy pinkNone 9 ¹Eriochrome blue Monoazo 14640 Muddy pink None black B 10¹Aniline blue Methane 42780 Blue Gray/green 11 ¹Azure B Thiazine 52010Blue Significantly lighter 12 ¹Guinea green B Methane 42085 Green Almostcolorless (Acid green 3) 13 ⁴D & C green No. 5 Anthraquinone Not knownPale green None 14 ⁴Keystone soap Not known Not known Light green Nonefluoro green 15 ¹Congo red Diazo 22120 Red None 16 ¹Acid blue 113 Diazo26360 Blue/gray None 17 ¹Acid red 151 Diazo 26900 Pink None 18 ¹Arsenazo1 Monoazo None Light pink Slightly lighter 19 ¹Methylene violet Diazine50206 Pink None 3RAX 20 ¹Mordant brown 48 Monoazo 11300 Very lightorange None 21 ²Basic red 14 Not known Not known Pink Slightly lighter22 ²Basic red 15 Not known Not known Pink Slightly lighter 23 ¹Fastgreen FCF Methane 42053 Green None 24 ¹Erioglaucine Methane 42090Green/blue None 25 ³Alkali blue 4B Methane 42750 Blue Slightly lighter26 ³Coomassie violet R Methane 42650 Grey/blue None 150 27 ¹Acid blue 92Monoazo 13390 Lilac Light violet 28 ¹Acid blue 29 Diazo 20460 Grey/blueNone 29 ¹Xylidine ponceau Monoazo 16150 Orange None 2R 30 ¹Reactive blue2 Anthraquinone 61211 Blue/gray None

[0112] TABLE 3b Indicator Composition 3 Colorants and Results afterSterilization Color Index Color with Cobalt No. Colorant Colorant ClassNumber Initial Color Chloride Color Change in Sterilizer 1 ³Patent blueMethane None Green/blue Green/blue Colorless violet 2 ¹Aniline blueMethane 42780 Blue Blue Colorless 3 ¹Congo red Diazo 22120 Dark orangeDark orange Colorless 4 ¹Arsenazo 1 Monoazo None Light Pink GreyColorless 5 ¹Acid blue 92 Monoazo 13390 Lilac Lilac Colorless 6 ¹Acidblue 29 Diazo 20460 Gray/blue Gray/blue Colorless

[0113] TABLE 4 Indicator Composition 4 Colorants and Results afterSterilization Color Index Color with Cobalt Color Change in No. ColorantColorant Class Number Initial Color Acetate Sterilizer 1 ¹Nile blue AOxazine 51180 Lilac Lilac Colorless 2 ¹Eriochrome Monoazo 14640 Muddypink Light violet Colorless blue black B 3 ⁴D & C green AnthraquinoneNot known Light green Light green Colorless No. 5 4 ²Basic red 15 Notknown Not known Pink Pink Colorless 5 ¹Erioglaucine Methane 42090Green/blue Green/blue Colorless 6 ¹Reactive blue 2 Anthraquinone 61211Blue/gray Blue/gray Colorless

[0114] TABLE 5 Indicator Compositios 5 Colorants and Results afterSterilization Color Index Initial Color with Cupric Color Change in No.Colorant Colorant Class Number Color Chloride Sterilizer 1 ¹Azocarmine GDiazine 50085 Rose Light rose Colorless 2 ¹Victoria pure blue Methane42595 Blue Dank blue Colorless BO (Basic blue 7) 3 ¹Acid fuchsin Methane42685 Hot pink Pink Colorless sodium salt 4 ⁴D & C green No. 5Anthraquinone Not known Pale green Very pale green Colorless 5 ⁴Keystonesoap Not known Not known Light green Light green Colorless fluoro green6 ²Basic red 14 Not known Not known Pink Pink Colorless

[0115] TABLE 6 Indicator Composition 6 Colorants and Results afterSterilization Color Colorant Index Color with No. Colorant Class NumberInitial Color Cupric Sulfate Color Change in Sterilizer 1 ²Patent blueMethane None Green/blue Green/blue Green/gray violet 2 ¹Azure B Thiazine52010 Blue Blue Clear 3 ¹Guinea green B Methane 42085 Green GreenMottled green on clear (Acid green 3) 4 ¹Methylene Diazine 50206 PinkPink Almost colorless violet 3RAX 5 ²Basic red 15 Not known Not knownPink Pink Significantly lighter 6 ¹Fast green FCF Methane 42053 GreenGreen Mottled green on clear

[0116] TABLE 7 Indicator Composition 7 Colorants and Results afterSterilization Color Index Color with Ferrous Color Change in No.Colorant Colorant Class Number Initial Color Chloride Sterilizer 1¹Azocarmine G Diazine 50085 Rose Light rose Colorless 2 ¹Victoria pureMethane 42595 Blue Dark blue Colorless blue BO (Basic blue 7) 3 ¹Acidfuchsin Methane 42685 Hot pink Pink Colorless sodium salt 4 ⁴D & C greenAnthraquinone Not known Pale green Very pale green Colorless No. 5 5⁴Keystone soap Not known Not known Light green Light green Colorlessfluoro green 6 ²Basic red 14 Not known Not known Pink Pink Colorless

[0117] TABLE 8 Indicator Composition 8 Colorants and Results afterSterilization Colorant Color Index Color with Color Change in No.Colorant Class Number Initial Color Ferrous Sulfate Sterilizer 1 ²Patentblue Methane None Green/blue Green/blue Significantly, Lighter violet 2¹Eriochrome Monoazo 14645 Light muddy pink Light brown Colorless black T3 ¹Eriochrome Monoazo 14640 Muddy pink Pale pink Colorless blue black B4 ¹Acid blue 113 Diazo 26360 Blue/gray Blue/gray Colorless 5 ¹Acid red151 Diazo 26900 Pink Pink Almost Colorless 6 ³Alkali blue 4B Methane42750 Blue Blue Significantly, lighter

[0118] TABLE 9 Indicator Composition 9 Colorants and Results afterSterilization Color with Colorant Color Index Chromium Color Change inNo. Colorant Class Number Initial Color Potassium Sulfate Sterilizer 1¹Ethyl violet (Basic Methane 42600 Dark Dark purple/blue Colorlessviolet 4) purple/blue 2 ¹Quinaldine red Cyanine None Muddy pink Muddypink Colorless 3 ¹Eriochrome black T Monoazo 14645 Very light Lightmuddy pink Colorless muddy pink 4 ¹Eriochrome blue Monoazo 14640 Muddypink Muddy pink Colorless black B 5 ¹Congo red Diazo 22120 Red Red Brown6 ¹Acid blue 113 Diazo 26360 Blue/gray Blue/gray Colorless

[0119] TABLE 10 Indicator Composition 10 Colorants and Results afterSterilization Color Index Color with Cupric Color Change in No. ColorantColorant Class Number Initial Color Acetate Sterilizer 1 ¹Acid red 151Diazo 26900 Pink Very pale pink, Lighter almost clear 2 ¹Mordant brown48 Monoazo 11300 Very Light Cream Lighter Orange 3 ³Coomassie violet R150 Methane 42650 Gray/blue Purple Almost colorless 4 ¹Acid blue 29Diazo 20460 Purple Pale purple Lighter 5 ¹Xylidine ponceau 2R Monoazo16150 Orange Yellow None 6 ¹Reactive blue 2 Anthraquinone 61211Blue/gray Blue/gray Slightly lighter

[0120] TABLE 11 Indicator Composition 11 Colorants and Results afterSterilization Colorant Color Index Color with Cupric No. Colorant ClassNumber Initial Color Acetate Color Change in Sterilizer 1 Evans blueDiazo 23860 Bright blue Bright blue Muddy light purple 2 Acid violet 7¹Monoazo 18055 Magenta Very dark pink Pale yellow with a slightly pinkcenter 3 Naphthol blue Diazo 20470 Navy blue Dark blue Dark purple black4 Reactive black 5¹ Diazo 20505 Blue Blue Pink* 5 Brilliant black Diazo28440 Dark blue Dark blue Off-white with light blue BN¹ center 6Brilliant black Diazo 28440 Dark blue Dark blue Off-white* BN¹ 7Azocarmine B Diazine 50090 Fuchsia Tan Yellow with a purple center 8Azocarmine B Diazine 50090 Fuchsia Tan Yellow*

[0121] TABLE 12 Indicator Composition 12 Colorants and Results afterSterilization Colorant Color Index Color with Cobalt No. Colorant ClassNumber Initial Color Acetate Color Change in Sterilizer 1 Cibacronbrilliant Monoazo 18105 Fuchsia Fuchsia Muddy yellow-green with a red3B¹ pink center 2 Evans blue Diazo 23860 Bright blue Bright blue Muddybrown with a slightly blue center 3 Reactive black 5¹ Diazo 20505 BlueBlue Pale blue with white edges 4 Reactive black 5¹ Diazo 20505 BlueBlue Pale spotty blue with white edges* 5 Brilliant black BN¹ Diazo28440 Dark blue Dark blue Muddy light brown with slightly blue center

[0122] TABLE 13 Indicator Composition 13 Colorants and Results afterSterilization Colorant Color Index Color with Cupric No. Colorant ClassNumber Initial Color Sulfate Color Change in Sterilizer 1 Evans blueDiazo 23860 Bright blue Bright blue Dark Blue 2 Acid violet 7¹ Monoazo18055 Magenta Magenta Pale pink 3 Acid violet 7¹ Monoazo 18055 MagentaMagenta Pale yellow* 4 Naphthol blue black Diazo 20470 Navy blue Navyblue Muddy magenta with tan spots* 5 Reactive black 5¹ Diazo 20505 BlueBlue Dark pink 6 Brilliant black BN¹ Diazo 28440 Dark blue Dark blueSlight lighter blue 7 Azocarmine B Diazine 50090 Fuchsia Coral Purple

[0123] The complete disclosures of the patents, patent documents, andpublications cited herein are incorporated by reference in theirentirety as if each were individually incorporated. Variousmodifications and alterations to this invention will become apparent tothose skilled in the art without departing from the scope and spirit ofthis invention. It should be understood that this invention is notintended to be unduly limited by the illustrative embodiments andexamples set forth herein and that such examples and embodiments arepresented by way of example only with the scope of the inventionintended to be limited only by the claims set forth herein as follows.

What is claimed is:
 1. A sterilization indicator comprising a substrateand an indicator composition disposed thereon, wherein the indicatorcomposition comprises: at least one salt of a transition metal; at leastone colorant that changes color when exposed to a sterilant; and atleast one binder resin.
 2. The sterilization indicator of claim 1,wherein the transition metal is selected from the group consisting ofGroup VIB, Group VIII, and Group IB transition metals, and combinationsthereof.
 3. The sterilization indicator of claim 1, wherein thesterilant is hydrogen peroxide or peracetic acid.
 4. The sterilizationindicator of claim 1, wherein the colorant is selected from the group ofclasses of colorants consisting of Methane, Monoazo, Diazo, Triazo,Diazine, Thiazine, Xanthene, Oxazine, Cyanine, Anthraquinone,Benzodifuranone, Styryl, Phthalocyanine, Quinophthalone, Nitro, andNitroso colorants, and combinations thereof, and/or the colorant isselected from the group consisting of Victoria green S extra, Basic blue41, Basic red 15, Acid green AX986, Keystone soap fluoro green, Basicred 14, and combinations thereof.
 5. The sterilization indicator ofclaim 1, wherein the indicator composition further comprises at leastone colorant that does not change color when exposed to the sterilant.6. A hydrogen peroxide indicator comprising a substrate and an indicatorcomposition disposed thereon, wherein the indicator compositioncomprises: at least one salt of a transition metal; at least onecolorant selected from the group of classes of colorants consisting ofMethane, Monoazo, Diazo, Triazo, Diazine, Thiazine, Xanthene, Oxazine,and Anthraquinone colorants, and combinations thereof, and/or at leastone colorant selected from the group consisting of Victoria green Sextra, Basic blue 41, Basic red 15, Acid green AX986, Keystone soapfluoro green, Basic red 14, and combinations thereof; and at least onebinder resin.
 7. The hydrogen peroxide indicator of claim 6, wherein theindicator composition further comprises at least one colorant that doesnot change color when exposed to hydrogen peroxide vapor.
 8. Thehydrogen peroxide indicator of claim 6, wherein the salt of a transitionmetal is selected from the group consisting of a copper salt, a cobaltsalt, an iron salt, a chromium salt, and combinations thereof.
 9. Thehydrogen peroxide indicator of claim 8, wherein the indicator comprisesat least one iron salt.
 10. The hydrogen peroxide indicator of claim 9,wherein the colorant is selected from the group consisting of Patentblue violet, Alkali blue 4B, Victoria pure blue BO, Acid fuchsin sodiumsalt, Alphazurine A, Methyl violet 2B, Ethyl violet, FD/C blue 1,Brilliant blue R, Lissamine green B, Erioglaucine, Eriochrome black T,Eriochrome blue black B, Cibacron brilliant red 3B, Chromotrope 2B,Amaranth, D&C red No. 33, Bordeaux R, Acid violet 7, Acid violet 5,Plasmocorinth B, Acid blue 113, Acid red 151, Acid black 24, Acid red97, Direct red 75, Brilliant crocein MOO, Ponceau SS, Reactive black 5,Arsenazo 111, Direct blue 71, Azocarmine G, Methylene violet 3RAX,Toluidine blue O, Methylene green, Sulforhodamine B, Rhodanine 6G,Violamine R, Nile blue A, Basic blue 3, Brilliant cresyl blue BB, Basicred 15, Alizarin violet 3R, Victoria green S extra, Basic blue 41, Acidgreen AX986, Keystone soap fluoro green, Basic red 14, D&C green No. 5,and combinations thereof.
 11. The hydrogen peroxide indicator of claim10, wherein the colorant is selected from the group consisting ofVictoria pure blue BO, Acid fuchsin sodium salt, Alphazurine A, Methylviolet 2B, Ethyl violet, FD/C blue 1, Brilliant blue R, Lissamine greenB, Erioglaucine, Eriochrome black T, Eriochrome blue black B, Cibacronbrilliant red 3B, Chromotrope 2B, D&C red No. 33, Acid violet 7, Acidviolet 5, Plasmocorinth B, Acid blue 113, Acid red 151, Acid black 24,Acid red 97, Direct red 75, Brilliant crocein MOO, Ponceau SS, Reactiveblack 5, Arsenazo 111, Azocarmine G, Methylene violet 3RAX, Toluidineblue O, Methylene green, Sulforhodamine B, Rhodanine 6G, Violamine R,Nile blue A, Basic blue 3, Brilliant cresyl blue BB, Basic red 15,Alizarin violet 3R, Victoria green S extra, Basic blue 41, Acid greenAX986, Keystone soap fluoro green, Basic red 14, D&C green No. 5, andcombinations thereof.
 12. A hydrogen peroxide indicator comprising asubstrate and an indicator composition disposed thereon, wherein theindicator composition comprises: at least one salt of cobalt, copper,chromium, and combinations thereof; at least one colorant that changescolor when exposed to hydrogen peroxide vapor; and at least one binderresin.
 13. The hydrogen peroxide indicator of claim 12, wherein the saltis selected from the group consisting of cobalt chloride, cobaltacetate, cupric chloride, cupric sulfate, cupric acetate, chromiumpotassium sulfate, and combinations thereof.
 14. The hydrogen peroxideindicator of claim 12, wherein the colorant is selected from the groupof classes of colorants consisting of Methane, Monoazo, Diazo, Triazo,Diazine, Thiazine, Cyanine, Xanthene, Oxazine, and Anthraquinonecolorants, and combinations thereof, and/or the colorant is selectedfrom the group consisting of Victoria green S extra, Basic blue 41,Basic red 15, Acid green AX986, Keystone soap fluoro green, Basic red14, and combinations thereof.
 15. The hydrogen peroxide indicator ofclaim 12, wherein the indicator composition further comprises at leastone colorant that does not change color when exposed to hydrogenperoxide vapor.
 16. The hydrogen peroxide indicator of claim 12, whereinthe indicator composition comprises at least one cobalt salt.
 17. Thehydrogen peroxide indicator of claim 16, wherein the colorant isselected from the group of classes of colorants consisting of Methane,Monoazo, Diazo, Oxazine, and Anthraquinone colorants, and combinationsthereof.
 18. The hydrogen peroxide indicator of claim 17, wherein thecolorant is selected from the group consisting of Patent blue violet,Aniline blue, Erioglaucine, Arsenazo 1, Acid blue 92, Eriochrome blueblack B, Congo red, Acid blue 29, Nile blue A, Reactive blue 2, Basicred 15, D&C green No. 5, and combinations thereof.
 19. The hydrogenperoxide indicator of claim 12, wherein the indicator comprises at leastone copper salt.
 20. The hydrogen peroxide indicator of claim 19,wherein the colorant is selected from the group of classes of colorantsconsisting of Methane, Monoazo, Diazo, Triazo, Diazine, Thiazine,Xanthene, Oxazine, Cyanine, and Anthraquinone colorants, andcombinations thereof, and/or the colorant is selected from the groupconsisting of Victoria green S extra, Basic blue 41, Basic red 15, Acidgreen AX986, Keystone soap fluoro green, Basic red 14, and combinationsthereof.
 21. The hydrogen peroxide indicator of claim 20, wherein thecolorant is selected from the group consisting of Alphazurine A, Methylviolet 2B, Ethyl violet, FD/C blue 1, Brilliant blue R, Lissamine greenB, Erioglaucine, Victoria pure blue BO, Acid fuchsin sodium salt, Patentblue violet, Guinea green B, Coomassie violet R 150, Mordant brown 48,Chromotrope 2B, D&C red No. 33, Bordeaux R, Acid violet 7, Acid violet5, Plasmocorinth, Acid red 151, Acid blue 29, Acid black 24, Acid red97, Direct red 75, Brilliant crocein MOO, Ponceau SS, Reactive black 5,Arsenazo 111, Direct blue 71, Azocarmine G, Methylene violet 3RAX,Toluidine blue O, Azure B, Methylene green, Sulforhodamine B, Rhodanine6G, Violamine R, Nile blue A, Basic blue 3, Brilliant cresyl blue BB,Quinaldine red, Basic red 15, Alizarin violet 3R, Reactive blue 2,Victoria green S extra, Basic blue 41, Acid green AX986, Keystone soapfluoro green, Basic red 14, D&C green No. 5, Fast green FCF, andcombinations thereof.
 22. The hydrogen peroxide indicator of claim 20,wherein the colorant is selected from the group of classes of colorantsconsisting of Methane, Monoazo, Diazo, Diazine, Thiazine, Xanthene,Oxazine, and Cyanine colorants, and combinations thereof, and/or thecolorant is selected from the group consisting of Victoria green Sextra, Basic blue 41, Basic red 15, Acid green AX986, Keystone soapfluoro green, Basic red 14, and combinations thereof.
 23. The hydrogenperoxide indicator of claim 22, wherein the colorant is selected fromthe group consisting of Alphazurine A, Methyl violet 2B, Ethyl violet,FD/C blue 1, Brilliant blue R, Lissamine green B, Erioglaucine, Victoriapure blue BO, Acid fuchsin sodium salt, Coomassie violet R 150, Mordantbrown 48, Acid violet 5, Plasmocorinth, Acid red 151, Acid blue 29, Acidblack 24, Acid red 97, Direct red 75, Arsenazo 111, Azocarmine G,Methylene violet 3RAX, Toluidine blue O, Methylene green, Rhodanine 6G,Basic blue 3, Brilliant cresyl blue BB, Quinaldine red, Basic red 15,Reactive blue 2, Victoria green S extra, Basic blue 41, Keystone soapfluoro green, Basic red 14, D&C green No. 5, and combinations thereof.24. The hydrogen peroxide indicator of claim 12, wherein the indicatorcomprises at least one chromium salt.
 25. The hydrogen peroxideindicator of claim 24, wherein the colorant is selected from the groupof classes of colorants consisting of Methane, Monoazo, Diazo, andCyanine colorants, and combinations thereof.
 26. The hydrogen peroxideindicator of claim 25, wherein the colorant is selected from the groupconsisting of Ethyl violet, Eriochrome black T, Eriochrome blue black B,Congo red, Acid blue 113, Quinaldine red, and combinations thereof. 27.The hydrogen peroxide indicator of claim 26, wherein the colorant isselected from the group consisting of Ethyl violet, Eriochrome black T,Eriochrome blue black B, Acid blue 113, Quinaldine red, and combinationsthereof.
 28. A peracetic acid indicator comprising a substrate and anindicator composition disposed thereon, wherein the indicatorcomposition comprises: at least one salt of a transition metal; at leastone colorant selected from the group of classes of colorants consistingof Monoazo and Diazo colorants, and combinations thereof, and/or atleast one colorant selected from the group consisting of Victoria greenS extra, Basic blue 41, Basic red 15, Acid green AX986, Keystone soapfluoro green, Basic red 14, and combinations thereof; and at least onebinder resin.
 29. The peracetic acid indicator of claim 28, wherein theindicator composition further comprises at least one colorant that doesnot change color when exposed to peracetic acid.
 30. A peracetic acidindicator comprising a substrate and an indicator composition disposedthereon, wherein the indicator composition comprises: at least one saltof copper, cobalt, and combinations thereof; at least one colorant thatchanges color when exposed to peracetic acid; and at least one binderresin.
 31. The peracetic acid indicator of claim 30, wherein theindicator composition further comprises at least one colorant that doesnot change color when exposed to peracetic acid.
 32. The peracetic acidindicator of claim 30, wherein the indicator composition comprises atleast one copper salt.
 33. The peracetic acid indicator of claim 32,wherein the colorant is selected from the group of classes of colorantsconsisting of Monoazo and Diazo colorants, and combinations thereof,and/or the colorant is selected from the group consisting of Victoriagreen S extra, Basic blue 41, Basic red 15, Acid green AX986, Keystonesoap fluoro green, Basic red 14, and combinations thereof.
 34. Theperacetic acid indicator of claim 33, wherein the colorant is selectedfrom the group consisting of Acid violet 7, Evans blue, Naphthol blueblack, Reactive black 5, Brilliant black BN, Azocarmine B, andcombinations thereof.
 35. The peracetic acid indicator of claim 30,wherein the indicator composition comprises at least one cobalt salt.36. The peracetic acid indicator of claim 35, wherein the colorant isselected from the group of classes of colorants consisting of Monoazoand Diazo colorants, and combinations thereof.
 37. The peracetic acidindicator of claim 36, wherein the colorant is selected from the groupconsisting of Cibacron brilliant red 3B, Evans blue, Reactive black 5,Brilliant black BN, and combinations thereof.
 38. A method of monitoringa sterilization process, the method comprising: providing an indicatorcomprising a substrate and an indicator composition comprising: at leastone salt of a transition metal; at least one colorant that changes colorwhen exposed to a sterilant; and at least one binder resin; providing anarticle to be sterilized; and exposing the indicator and the article tobe sterilized to a sterilant.
 39. A method of monitoring a hydrogenperoxide sterilization process, the method comprising: providing ahydrogen peroxide indicator comprising a substrate and an indicatorcomposition comprising: at least one salt of a transition metal; atleast one colorant selected from the group of classes of colorantsconsisting of Methane, Monoazo, Diazo, Triazo, Diazine, Thiazine,Cyanine, Xanthene, Oxazine, Anthraquinone, Benzodifuranone, Styryl,Phthalocyanine, Quinophthalone, Nitro, and Nitroso colorants, andcombinations thereof, and/or at least one colorant selected from thegroup consisting of Victoria green S extra, Basic blue 41, Basic red 15,Acid green AX986, Keystone soap fluoro green, Basic red 14, andcombinations thereof; and at least one binder resin; providing anarticle to be sterilized; and exposing the hydrogen peroxide indicatorand the article to be sterilized to hydrogen peroxide vapor.
 40. Themethod of claim 39, wherein the salt of a transition metal is selectedfrom the group consisting of cupric chloride, ferrous chloride, cobaltchloride, cobalt acetate, cupric sulfate, ferrous sulfate, chromiumpotassium sulfate, cupric acetate, and combinations thereof.
 41. Themethod of claim 39, wherein the indicator composition further comprisesat least one colorant that does not change color when exposed tohydrogen peroxide vapor.
 42. A method of monitoring a hydrogen peroxidesterilization process, the method comprising: providing a hydrogenperoxide indicator comprising a substrate and an indicator compositioncomprising: at least one salt of copper, chromium, iron, cobalt, andcombinations thereof; at least one colorant that changes color whenexposed to hydrogen peroxide vapor; and at least one binder resin;providing an article to be sterilized; and exposing the hydrogenperoxide indicator and the article to be sterilized to hydrogen peroxidevapor.
 43. The method of claim 42, wherein the colorant is selected fromthe group of classes of colorants consisting of Methane, Monoazo, Diazo,Triazo, Diazine, Thiazine, Cyanine, Xanthene, Oxazine, Anthraquinonecolorants, and combinations thereof, and/or the colorant is selectedfrom the group consisting of Victoria green S extra, Basic blue 41,Basic red 15, Acid green AX986, Keystone soap fluoro green, Basic red14, and combinations thereof.
 44. The method of claim 42, wherein theindicator composition comprises at least one cobalt salt.
 45. The methodof claim 44, wherein the colorant is selected from the group of classesof colorants consisting of Methane, Monoazo, Diazo, Oxazine, andAnthraquinone colorants, and combinations thereof.
 46. The method ofclaim 45, wherein the colorant is selected from the group consisting ofPatent blue violet, Aniline blue, Erioglaucine, Arsenazo 1, Acid blue92, Eriochrome blue black B, Congo red, Acid blue 29, Nile blue A,Reactive blue 2, Basic red 15, D&C green No. 5, and combinationsthereof.
 47. The method of claim 42, wherein the indicator compositioncomprises at least one copper salt.
 48. The method of claim 47, whereinthe colorant is selected from the group of classes of colorantsconsisting of Methane, Monoazo, Diazo, Triazo, Diazine, Thiazine,Xanthene, Oxazine, Cyanine, and Anthraquinone colorants, andcombinations thereof, and/or the colorant is selected from the groupconsisting of Victoria green S extra, Basic blue 41, Basic red 15, Acidgreen AX986, Keystone soap fluoro green, Basic red 14, and combinationsthereof.
 49. The method of claim 48, wherein the colorant is selectedfrom the group consisting of Alphazurine A, Methyl violet 2B, Ethylviolet, FD/C blue 1, Brilliant blue R, Lissamine green B, Erioglaucine,Victoria pure blue BO, Acid fuchsin sodium salt, Patent blue violet,Guinea green B, Coomassie violet R 150, Mordant brown 48, Chromotrope2B, D&C red No. 33, Bordeaux R, Acid violet 7, Acid violet 5,Plasmocorinth, Acid red 151, Acid blue 29, Acid black 24, Acid red 97,Direct red 75, Brilliant crocein MOO, Ponceau SS, Reactive black 5,Arsenazo 111, Direct blue 71, Azocarmine G, Methylene violet 3RAX,Toluidine blue O, Azure B, Methylene green, Sulforhodamine B, Rhodanine6G, Violamine R, Nile blue A, Basic blue 3, Brilliant cresyl blue BB,Quinaldine red, Basic red 15, Alizarin violet 3R, Reactive blue 2,Victoria green S extra, Basic blue 41, Acid green AX986, Keystone soapfluoro green, Basic red 14, D&C green No. 5, Fast green FCF, andcombinations thereof.
 50. The method of claim 49, wherein the colorantis selected from the group consisting of Alphazurine A, Methyl violet2B, Ethyl violet, FD/C blue 1, Brilliant blue R, Lissamine green B,Erioglaucine, Victoria pure blue BO, Acid fuchsin sodium salt, Coomassieviolet R 150, Mordant brown 48, Acid violet 5, Plasmocorinth, Acid red151, Acid blue 29, Acid black 24, Acid red 97, Direct red 75, Arsenazo111, Azocarmine G, Methylene violet 3RAX, Toluidine blue 0, Methylenegreen, Rhodanine 6G, Basic blue 3, Brilliant cresyl blue BB, Quinaldinered, Basic red 15, Reactive blue 2, Victoria green S extra, Basic blue41, Keystone soap fluoro green, Basic red 14, D&C green No. 5, andcombinations thereof.
 51. The method of claim 42, wherein the indicatorcomposition comprises at least one iron salt.
 52. The method of claim51, wherein the colorant is selected from the group of classes ofcolorants consisting of Methane, Monoazo, Diazo, Triazo, Diazine,Thiazine, Cyanine, Xanthene, Oxazine, and Anthraquinone colorants, andcombinations thereof, and/or the colorant is selected from the groupconsisting of Victoria green S extra, Basic blue 41, Basic red 15, Acidgreen AX986, Keystone soap fluoro green, Basic red 14, and combinationsthereof.
 53. The method of claim 52, wherein the colorant is selectedfrom the group consisting of Patent blue violet, Alkali blue 4B,Victoria pure blue BO, Acid fuchsin sodium salt, Alphazurine A, Methylviolet 2B, Ethyl violet, FD/C blue 1, Brilliant blue R, Lissamine greenB, Erioglaucine, Eriochrome black T, Eriochrome blue black B, Cibacronbrilliant red 3B, Chromotrope 2B, Amaranth, D&C red No. 33, Bordeaux R,Acid violet 7, Acid violet 5, Plasmocorinth B, Acid blue 113, Acid red151, Acid black 24, Acid red 97, Direct red 75, Brilliant crocein MOO,Ponceau SS, Reactive black 5, Arsenazo 111, Direct blue 71, AzocarmineG, Methylene violet 3RAX, Toluidine blue O, Methylene green,Sulforhodamine B, Rhodanine 6G, Violamine R, Nile blue A, Basic blue 3,Brilliant cresyl blue BB, Quinaldine red, Basic red 15, Alizarin violet3R, Victoria green S extra, Basic blue 41, Acid green AX986, Keystonesoap fluoro green, Basic red 14, D&C green No. 5, and combinationsthereof.
 54. The method of claim 53, wherein the colorant is selectedfrom the group consisting of Victoria pure blue BO, Acid fuchsin sodiumsalt, Alphazurine A, Methyl violet 2B, Ethyl violet, FD/C blue 1,Brilliant blue R, Lissamine green B, Erioglaucine, Eriochrome black T,Eriochrome blue black B, Cibacron brilliant red 3B, Chromotrope 2B, D&Cred No. 33, Acid violet 7, Acid violet 5, Plasmocorinth B, Acid blue113, Acid red 151, Acid black 24, Acid red 97, Direct red 75, Brilliantcrocein MOO, Ponceau SS, Reactive black 5, Arsenazo 111, Azocarmine G,Methylene violet 3RAX, Toluidine blue O, Methylene green, SulforhodamineB, Rhodanine 6G, Violamine R, Nile blue A, Basic blue 3, Brilliantcresyl blue BB, Basic red 15, Alizarin violet 3R, Victoria green Sextra, Basic blue 41, Acid green AX986, Keystone soap fluoro green,Basic red 14, D&C green No. 5, and combinations thereof.
 55. The methodof claim 42, wherein the indicator composition comprises a chromiumsalt.
 56. The method of claim 55, wherein the colorant is selected fromthe group of classes of colorants consisting of Methane, Monoazo, Diazo,and Cyanine colorants, and combinations thereof.
 57. The method of claim56, wherein the colorant is selected from the group consisting of Ethylviolet, Eriochrome black T, Eriochrome blue black B, Congo red, Acidblue 113, Quinaldine red, and combinations thereof.
 58. The method ofclaim 57 wherein the colorant is selected from the group consisting ofEthyl violet, Eriochrome black T, Eriochrome blue black B, Acid blue113, Quinaldine red, and combinations thereof.
 59. A method ofmonitoring a peracetic acid sterilization process, the methodcomprising: providing a peracetic acid indicator comprising a substrateand an indicator composition comprising: at least one salt of atransition metal; at least one colorant selected from the group ofclasses of colorants consisting of Monoazo, Diazo, Benzodifuranone,Styryl, Phthalocyanine, Quinophthalone, Nitro, and Nitroso colorants,and combinations thereof, and/or at least one colorant selected from thegroup consisting of Victoria green S extra, Basic blue 41, Basic red 15,Acid green AX986, Keystone soap fluoro green, Basic red 14, andcombinations thereof; and at least one binder resin; providing anarticle to be sterilized; and exposing the peracetic acid indicator andthe article to be sterilized to liquid peracetic acid.
 60. The method ofclaim 59 wherein the salt of a transition metal is selected from thegroup consisting of cupric acetate, cobalt acetate, cupric sulfate, andcombinations thereof.
 61. A method of monitoring a peracetic acidsterilization process, the method comprising: providing a peracetic acidindicator comprising a substrate and an indicator compositioncomprising: at least one salt of copper, cobalt, and combinationsthereof; at least one colorant that changes color when exposed to liquidperacetic acid; and at least one binder resin; providing an article tobe sterilized; and exposing the peracetic acid indicator and the articleto be sterilized to liquid peracetic acid.
 62. The method of claim 61,wherein the colorant is selected from the group of classes of colorantsconsisting of Monoazo and Diazo colorants, and combinations thereof,and/or the colorant is selected from the group consisting of Victoriagreen S extra, Basic blue 41, Basic red 15, Acid green AX986, Keystonesoap fluoro green, Basic red 14, and combinations thereof.
 63. Themethod of claim 61, wherein the indicator composition comprises at leastone copper salt.
 64. The method of claim 63, wherein the colorant isselected from the group of classes of colorants consisting of Monoazoand Diazo colorants, and combinations thereof, and/or the colorant isselected from the group consisting of Victoria green S extra, Basic blue41, Basic red 15, Acid green AX986, Keystone soap fluoro green, Basicred 14, and combinations thereof.
 65. The method of claim 64, whereinthe colorant is selected from the group consisting of Acid violet 7,Evans blue, Naphthol blue black, Reactive black 5, Brilliant black BN,Azocarmine B, and combinations thereof.
 66. The method of claim 61,wherein the indicator composition comprises at least one cobalt salt.67. The method of claim 66, wherein the colorant is selected from thegroup of classes of colorants consisting of Monoazo and Diazo colorants,and combinations thereof.
 68. The method of claim 67, wherein thecolorant is selected from the group consisting of Cibacron brilliant red3B, Evans blue, Reactive black 5, Brilliant black BN, and combinationsthereof.